[en] The various role of the formation of HDBP and H₂MBP in γ irradiated 30% TBP-Kerosene-1 mol/L HNO₃ mixed phase (with a phase ratio of 0/A = 1: 1) is studied. A comparative result in irradiated 30% TBP-Kerosene single organic phase has been made. It shows that in irradiated mixed phase, the major source of HDBP formation is the organic phase and the H₂MBP concentration yielded in irradiated mixed phase is 30%-40% higher than that in irradiated single phase. In addition, the HDBP G value in irradiated mixed phase is much high than that in irradiated single phase during the absorbed dose <2 x 10⁵ Gy, but when the absorbed dose >2 x 10⁵ Gy. there is no remarkable difference for it. The reason of the difference for the radiolysis of TBP in irradiated mixed phase and single phase has been discussed, the existence of much more O₂ and H₂O in irradiated mixed phase system plays a main role

[en] The effects of BSO, a potent radiosensitizing and chemical sensitizing chemical, on the incidence of micronuclei in four different cell lines have been studied using the cytokinesis-block (CB) method. The number of micronuclei in cultured human peripheral lymphocytes, Chinese hamster cells and human breast cancer cells were not affected by 0.1-2 mmol/L BSO treatment alone. However, significant increase in the incidence of micronuclei in these cells could be detected when BSO was used in combination with γ-irradiation. Linear relationship between the incidence of micronuclei and the radiation dose was observed

[en] Using the differential pulse polarography, the values of the half wave potential (E_1/2) of the new radiosensitizer CM, Misonidazole MISO and Metronidazole were measured, and also compared under the same condition. The results showed that the magnitude of the E_1/2 was as follows: MISO>CM>Metronidazole. The data demonstrates that their reduction ability correlates well with their radiosensitization. Although the electron affinity potency of CM and its radiosensitization in vitro are in the middle, CM has properties of tumor-affinity to a certain extent, low toxicity and high therapeutic index, and the preliminary clinical results indicate that CM is a low toxic and efficient radiosensitizer

[en] The male and female mice were irradiated with different doses (from 0 to 200 cGy) of ⁶⁰Co gamma ray, their splenic antibody forming cells were measured with the Plaque Forming Cell (PFC) technique. The results show that the PFCs of both the male and female mice were depressed and the depression was of dose-depending. When the dose was 200 cGy, about 85% of the PFCs were inhabited. No difference in the radiosensitivity between the male and female mice was found

[en] The radiation polymerization technique was used for immobilization testosterone propionate into crosslinked network of poly hydroxyethyl methacrylate to prepare slowly released male sex hormone drug which is used for testicular prosthesis. The testicular prosthesis was transplanted into the scrotum of male rabbit whose testes was excised 2 months before the transplantation. Then the level of male sex hormone in serum was measured by radioimmunoassay once a week after transplantation. The results of measurement in a period of 6 months were shown that the testicular prosthesis has a stable release of male sex hormone. The testosterone level in serum of the castrated male rabbits rises markedly and finally stabilizes at the level of 429 ± 36 ng/100 ml after transplantation. Macroscopic examination of biopsies taken from the tissues around the testicular prosthesis showed that tissue compatibility was revealed well

[en] The effects of electron beam irradiation on polyethylene foam of open cell type have been studied. Experiments for determining of gel fraction and physical-mechanical properties of irradiated polyethylene foam of open cell type as a function of dose, respectively, were carried out. The dimensional stability of irradiated specimens at elevated temperatures was measured. It was found that tensile strength did not change and gel fraction increased when the specimen was irradiated in nitrogen atmosphere with increasing dose up to 300 kGy. The result shows that dimensional stability of polyethylene foam of open cell type after being kept in an oven at 70 deg C and 110 deg C for 22 h is improved by irradiation in nitrogen atmosphere. The similar results of irradiated EVA foam of open cell type irradiated foam of open cell type were obtained

[en] The effects of a new radiosensitizing compound-metronidazolamic acid (CM) and its Ca⁺² chelation compound (CMCa) on the DNase activity of mouse hepatic tumor (H₂₂) cells were observed. The effects of CM, CMCa or Ca⁺² at same molarity and their combination with γ-rays irradiation on DNase activity of H₂₂ cells were also observed respectively. The results showed that CM could activate the DNase activity to be increased as CM concentration increased below 5 mmol/L. The highest DNase activity was activated by CM at 5 mmol/L. The degree of activation between CM and CMCa had no significant different (p > 0.05), whereas free Ca⁺² alone had no effect. The activation of combined CM or CMCa and radiation groups were greater than that of each given independently they possessed a coordinate activation. However free Ca⁺² still could not activate the DNase activity after γ-irradiation. From all the above results, it is suggested that CM or CMCa improved the tumor radiotherapeutic efficiency probable due to its activation the DNase activity of cancer cells which enhanced the DNA damage. It might be one of the radiosensitizing mechanism in tumor radiotherapy

[en] The polysaccharide from spirulina platensis (PSP) was further purified by sephadex G-100. PSP contained about 77.63% of sugar. The effect of PSP on immunological function of irradiated mice were studied. The results showed that PSP significantly improved organ weight, lymphocyte number and lymphocyte transformation in spleen of mice irradiated by 5 Gy

[en] Character change of operational amplifiers was compared in X- and γ-radiation environments. Dose enhancement effect of X- and γ-radiation was studied to operational amplifiers. Relative dose enhancement factors (RDEF) measured are about 3.4∼12.4 in the experiment. SiO₂/Si interface trapped hole charges and interface states are main failure model of operational amplifiers in X- and γ- radiation environments

[en] Effects of O₂ and dose rate on the radiolysis of rabbit hepatic metallothionein-I(MT-I) in phosphate buffer solution at pH 8.0 have been studied. Active species (OH and H₂O₂) formed under irradiation principally attack the Zn-S bonds in the β-domain of MT-I and as a result, give birth to disulfide bonds, and the formation of disulfide bonds mainly occurs intra-molecularly. The radiolysis of N₂- or N₂O-saturated MT-I solutions resulted in sulfhydryl-group-decrease with G_-SH- = 4.2 and 7.2 respectively, whereas G values of dimer (G_(MT-I)2) were only 0.32 and 0.67. A short chain-reaction exists in the decrease of sulfhydryl groups when O₂-saturated MT-I was irradiated, but it contributed little to G_(MT-I)2. However, the damaged MT-I can be repaired completely by reduced glutathione. The reaction between H₂O₂ and MT-I also was investigated, and k₂ = 10 mol· dm^-3s·^-1 for RS^-(MT-I) + H₂O₂ → RSOH + OH^- was obtained. Furthermore, the radiolysis mechanism of MT-I was discussed on the basis of above mentioned results and good material balances were achieved