AIM： To determine whether the number of non-rejoining G2-chromatid breaks can predict the radiosensitivity of human cell lines. METHODS： Cell lines of human ovary carcinoma cells （HO8910）, human hepatoma cells （H...AIM： To determine whether the number of non-rejoining G2-chromatid breaks can predict the radiosensitivity of human cell lines. METHODS： Cell lines of human ovary carcinoma cells （HO8910）, human hepatoma cells （HepG2） and liver cells （L02） were irradiated with a range of doses and assessed both of cell survival and non-rejoining G2-chromatid breaks at 24 h after irradiation. Cell survival was documented by a colony assay. Non-rejoining G2-chromatid breaks were measured by counting the number of non-rejoining G2 chromatid breaks at 24 h after irradiation, detected by the prematurely chromosome condensed （PCC） technique. RESULTS： A linear-quadratic survival curve was observed in three cell lines, and HepG2 was the most sensitive to γ-radiaUon. A dose-dependent linear increase was observed in radiation-induced non-rejoining G2- PCC breaks measured at 24 h after irradiation in all cell lines, and HepG2 was the most susceptible to induction of non-rejoining G2-PCC breaks. A close correlation was found between the clonogenic radiosensitivity and the radiation-induced non-rejoining G2-PCC breaks （r=0.923）. Furthermore, survival-aberration correlations for two or more than two doses lever were also significant. CONCLUSION： The number of non-rejoining G2 PCC breaks holds considerable promise for predicting the radiosensitMty of normal and tumor cells when two or more than two doses lever is tested.展开更多
Night sky cooling is explored as an alternative to the conventional cooling technologies using fossil fuels. The night sky cooling method is based on the long wave radiation of unglazed collectors to the sky at night....Night sky cooling is explored as an alternative to the conventional cooling technologies using fossil fuels. The night sky cooling method is based on the long wave radiation of unglazed collectors to the sky at night. An evaluation of the night sky cooling system is present for a residential building in three cities of Australia, namely Alice Springs, Darwin and Melbourne. The system comprises an unglazed flat plate solar collector integrated with borehole storage. It uses night sky radiation to reduce the temperature of the ground near to the boreholes. The system was simulated with TRNSYS, a transient simulation program. The simulation results for adequately sized systems show that night sky radiation is able to reduce the coolth storage borehole temperature and the proposed system is able to meet the cooling load of the residential building simulated in three locations. Borchole lengths of 270, 318 and 106 m are required for coolth storage with 90, 260 and 14 m2 collector area for heat rejection in Alice Springs, Darwin and Melbourne, respectively. At the 20th simulation year, the proposed system is able to achieve a system cooling coefficient of performance of 2.2 in Alice Springs, and 2.8 in Darwin and Melbourne.展开更多
基金Supported by the Key Project of National Natural Science Foundation of China, No. 10335050the Key Project of Ministry of Science and Technology of China, No. 2003CCB00200
文摘AIM： To determine whether the number of non-rejoining G2-chromatid breaks can predict the radiosensitivity of human cell lines. METHODS： Cell lines of human ovary carcinoma cells （HO8910）, human hepatoma cells （HepG2） and liver cells （L02） were irradiated with a range of doses and assessed both of cell survival and non-rejoining G2-chromatid breaks at 24 h after irradiation. Cell survival was documented by a colony assay. Non-rejoining G2-chromatid breaks were measured by counting the number of non-rejoining G2 chromatid breaks at 24 h after irradiation, detected by the prematurely chromosome condensed （PCC） technique. RESULTS： A linear-quadratic survival curve was observed in three cell lines, and HepG2 was the most sensitive to γ-radiaUon. A dose-dependent linear increase was observed in radiation-induced non-rejoining G2- PCC breaks measured at 24 h after irradiation in all cell lines, and HepG2 was the most susceptible to induction of non-rejoining G2-PCC breaks. A close correlation was found between the clonogenic radiosensitivity and the radiation-induced non-rejoining G2-PCC breaks （r=0.923）. Furthermore, survival-aberration correlations for two or more than two doses lever were also significant. CONCLUSION： The number of non-rejoining G2 PCC breaks holds considerable promise for predicting the radiosensitMty of normal and tumor cells when two or more than two doses lever is tested.
文摘Night sky cooling is explored as an alternative to the conventional cooling technologies using fossil fuels. The night sky cooling method is based on the long wave radiation of unglazed collectors to the sky at night. An evaluation of the night sky cooling system is present for a residential building in three cities of Australia, namely Alice Springs, Darwin and Melbourne. The system comprises an unglazed flat plate solar collector integrated with borehole storage. It uses night sky radiation to reduce the temperature of the ground near to the boreholes. The system was simulated with TRNSYS, a transient simulation program. The simulation results for adequately sized systems show that night sky radiation is able to reduce the coolth storage borehole temperature and the proposed system is able to meet the cooling load of the residential building simulated in three locations. Borchole lengths of 270, 318 and 106 m are required for coolth storage with 90, 260 and 14 m2 collector area for heat rejection in Alice Springs, Darwin and Melbourne, respectively. At the 20th simulation year, the proposed system is able to achieve a system cooling coefficient of performance of 2.2 in Alice Springs, and 2.8 in Darwin and Melbourne.
