[en] As an efficient and typical radiation source, heavy ion beam was widely used in biological mutagenesis breeding. The heavy ion beams of different mass, different charge number and different energy have their special processes and effects when interacting with the biological cells, which underwent physical, chemical and biological three stages, and led to end point biological effects ultimately, such as low doses of radiation sensitive phenomena and active oxygen metabolism changes. This article focuses on the primary endpoint of biological effect about the micro-organisms after the heavy ion beam irradiation, and the achievements made by heavy ion irradiation for microbial mutation breeding in agriculture and industry field in recent years. (authors)

[en] Flow cytometry analysis method was used to detect the changes of γH2AX protein expression in human peripheral blood lymphocytes. In the dose-effect study, peripheral blood was irradiated by ⁶⁰Co γ-rays with the dose of 0-6 Gy and cultivated for 1 h. Peripheral blood were cultivated for 0-24 h after 4 Gy ⁶⁰Co γ-rays irradiation for the time-effect study. Then, the peripheral blood was divided into four treatment groups, i.e. UV irradiation, ⁶⁰Co γ-rays irradiation, UV plus ⁶⁰Co γ-rays irradiation and control group to detect the changes of protein expression in different time. The results showed that the γH2AX protein expression was in a dose-dependent form. The expression of γH2AX peaked at 1 h after 4 Gy irradiation and began to decrease quickly. The expression of γH2AX in UV irradiation group increased compared with that of the sham-irradiation control group, and the expression of γH2AX peaked at 6 h. While compared with that of the ⁶⁰Co γ-rays group, the γH2AX expression of UV combined ⁶⁰Co γ-rays group was unchanged. The results reveal that the detection of γH2AX protein expression changes in peripheral blood lymphocyte by flow cytometry analysis is reasonable and may turns be a new way for biological dosimeter. (authors)

[en] Human lung cancer A549 and SPCA-1 cell lines were irradiated by X-rays at the absorbed doses of 1, 3, 5 and 8 Gy, respectively, generated by a linear accelerator (with the source skin distance of 100 cm and dose rate of 200 cGy·min^-1). The cell molecular samples were subtracted at 6 h, 12 h, and 24 h after 5 Gy ionizing irradiation. For the study of X-rays and cisplatin combination treatment, cells were divided into radiation group (5 Gy X-rays), cisplatin group (20 µmol·L^-1 cisplatin), and combination group (5 Gy X-rays + 20 µmol·L^-1 cisplatin). Untreated cells were classified as control group. The relative levels of BTG3 mRNA and protein expression in cells were detected by semi-quantitative RT-PCR and Western blot analysis with quantitation of the mRNA/protein bands by densitometry. The expression level of BTG3 mRNA and protein significantly increased with the dose climbed after radiation exposure of human lung cancer A549 and SPCA-1 cell lines (t = 5.25-15.75, p < 0.05). The expression level in cancer cells significantly increased 4 h after radiation exposure and kept increasing until 24 h later (t = 7.52-11.18, p < 0.05). Compared with that of the radiation and/or cisplatin treatment alone, more significant increase of BTG3 expression was identified after the combination treatment of X-rays and cisplatin (t = 7.02-15.86, p < 0.05). Ionizing radiation could up-regulate the expression of BTG3 in human lung cancer cells in both mRNA and protein levels. BTG3 gene may be targeted as a molecular for ionizing radiation and cisplatin treatment in lung cancer. (authors)

[en] The osteoblast was cultured from cranium of fetal rat with enzymatic digestion method; bone marrow lymphocyte was cultured by density gradient centrifugation; two kinds of cells were irradiated with ¹³⁷Cs γ-rays of 6 Gy; the groups were set as 0 Gy osteoblast+0 Gy lymphocyte(0OB0L), 0 Gy osteoblast+6 Gy lymphocyte(0OB6L), and 6 Gy osteoblast+6 Gy lymphocyte(6OB6L). After 6 h co-cultivation, the lymphocyte was co-cultured with normal osteoblast, and then the proliferation and differentiation of osteoblasts were detected by MTT and PNPP after 72 h, meanwhile, the mRNA expression of ALP, OCN, RANKL, and OPG of the osteoblast were detected after 2 h. The results suggest that radiated lymphocyte can inhibit the differentiation of osteoblast, down-regulate the mRNA expression of ALP and OCN, up-regulate the mRNA expression of RANKL and increase the ratio of RANKL/OPG. The radiated bone marrow lymphocyte not only suppresses the differentiation of osteoblast, but also affects the osteoclast by changing the ratio of RANKL/OPG. (authors)

[en] Nine patients suffering with left breast cancer after radical mastectomy and thirteen patients suffering with esophagus cancer were selected. All plan target volumes (PTV) included supraclavicular areas. Two IMRT plans (IMRT-PTV and IMRT-lung) for 22 patients were developed according to different isocenter positions (PTV center and the center determined by the lung volume in PTV). The dosimetric differences of PTV and normal tissues were analyzed using dose-volume histogram (DVH) for the two IMRT plans. The results showed that left lung V₂₀ and heart V₃₀ of the left breast cancer after radical mastectomy IMRT-lung plans dropped significantly (t = -6.154, -5.084; p = 0.038, 0.040), and left lung V₂₀, V₃₀, right lung V₃₀ and heart V₄₀ of the Esophagus cancer IMRT-Lung plans were also significantly lower (t = -7.493, -8.092, -6.332, -6.945; p = 0.025, 0.019, 0.042, 0.032), but not for other normal tissues. These findings indicate that changing isocenter position based on the lung volume involved in PTV can obtain the fewer dose of some normal tissues around the target volume. (authors)

[en] The beam dose distribution is compared with those obtained from Monte Carlo (MC) simulation and measurement to investigate dosimetry characteristics for X-ray fields. The beam data, including percentage depth dose (PDD) and off axis ratio (OAR), were acquired by measurement and MC calculation in water phantom for Varian 6 MV X-ray fields. The results were compared and analyzed. The match result, for PDD of the field of 10 cm × 10 cm, has shown 96.47% agreement for γ ≤ 1 with 2% delta dose and 2 mm DTA for calculated and measured dose distribution at the depth of 0 to 20 cm, and 99.23% for γ ≤ 1 with 3% delta dose and 3 mm DTA. The match result of OAR has shown 97.56% agreement for γ ≤ 1 with 2% delta dose and 2 mm DTA for calculated and measured dose distribution, and 99.42% for γ ≤ 1 with 3% delta dose and 3 mm DTA. Electron dose is 5.3% of depth dose for 10 cm × 10 cm, and 15.2% for 40 cm × 40 cm. Dose distribution can determined through the measurement and calculation in fields. (authors)

[en] In order to accurately grasp the actual protection effect of molecular sieve in the spot, it is necessary to take the experiment of tritium air (HTO) penetration experiment. With the nitrogen with certain dew point and tritium concentration passing through the molecular sieve with a steady flow and continuous measuring the changes of tritium concentration before and after the molecular sieve as well as the quality changes before and after the penetration, the tritium protection effect of molecular sieve in actual environment was determined. The experimental results show that the tritiated water adsorption effect of anhydrous molecular sieve is the best: the filtration efficiency within 4 h stays above 95% which has high efficiency and stays for a long time; the molecular sieve with 1/3 absorbed water shows a good performance which has a filtration efficiency maintaining above 90% within 3 h. Considering the comfortable degree and filtration efficiency, molecular sieve with 1/3 absorbed water is more suitable for practical tritium protection field. (authors)

[en] A polymerizable nanogel was synthesized with methacrylate-modified polysiloxane, urethane dimethacrylate and isobornyl methacrylate as main raw materials in the presence of a thiol chain transfer agent. The kinetics of photopolymerization, shrinkage stress, mechanical properties and thermostability of UV-cured materials with different contents of nanogel were investigated. The results indicated that the addition of nanogel could delay the onset of stress and further reduce the overall photopolymerization stress without compromising the mechanical properties of the resulting polymers, when the added mass fraction was within 20%. Moreover, with the addition of nanogel, the thermostability of the resulting polymer was strengthened. (authors)

[en] To prepare the lentivirus granules interfering lnc-RI and establish HeLa cell lines consistently down-regulating lnc-RI, as well as discover its effects on radiation damage, the lentivirus granules bearing various interfering sequences were prepared by lnc-RI carrying specific interfering sequences in to interfering plasmid pGLV2. The estable cell lines were established after infecting HeLa cells with lentivirus granules. RT-PCR was employed to determine the inhibitory effects of various interfering sequences on lnc-RI expression. DNA damage of the established estable cell lines were induced by ionizing radiation sensitivity of the established cell lines which were determined by colony formation assay. The results showed that the lentivirus granules bearing various interfering sequences were successfully prepared. The estable HeLa cell lines infected by lentivirus were obtained and lnc-RI expression levels was down-regulated. The results of colony formation assay showed that radiation sensitivity of the estable cell lines were increased when treated with each dose gamma ray irradiation. Thus, it is preliminarily proved the radiation sensitivity of the established cell lines were increased when treated with each dose gamma ray irradiation. (authors)

[en] To investigate the decorporation and radiation protection effects of WSC-DTPA nanoparticles on internal uranium exposure, the methods as followed were used. After SD rats were exposed to 0.5 mgU·kg^-1 uranyl nitrate by intraperitoneal injection, 92.7% WSC-DTPA nanoparticles, 1.59% WSC-DTPA nanoparticles, WSC nanoparticles and DTPA-CaNa₃ were administered at 60 mg·kg^-1 dose through tail vein immediately. The contents of uranium in urine and feces at 1^st, 2^nd and 3^rd day were measured by ICP, as well as those in liver, spleen, kidney and bone after 3 days. Exposed to 2.0 mgU·kg^-1 uranyl nitrate for 5 days, the contents of uranium in liver, spleen, kidney and bone were determined, and the functions of liver, spleen, kidney and bone were evaluated with pathological section and bone marrow cell smear. As a result, we found that 92.7% WSC-DTPA nanoparticles, 1.59% WSC-DTPA nanoparticles and DTPA-CaNa₃ have good decorporation effect, while 1.59% WSC-DTPA nanoparticles is significantly superior to DTPA-CaNa₃ (p < 0.05). At the group of 0.5 mgU·kg^-1, the uranium contents in liver, spleen, kidney and bone in treated groups are significantly lower than the control group. It is obvious that 92.7% WSC-DTPA nanoparticles have protective effects on liver and kidney by tissue pathological sections in the dose of 2.0 mgU·kg^-1. Therefore, it is suggested that 92.7% WSC-DTPA nanoparticles could have both good decorporation and radiation protective effects against the internal uranium exposure. (authors)