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  • 28 February 2014 Volume 23 Issue 1
      

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  • QIN Bin, LI Kang, YAO Zhu, ZHANG Wei, SU Xu
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    Objective To provide suggestions for ensuring a rational and orderly field medical emergency rescue, and minimizing the hazards of nuclear and radiation accidents. Methods According to domestic and foreign laws, regulations and standards, combined with the experience of our research involving in nuclear medicine and radiation accident emergency preparedness and response, the study of triage for wounded persons was carried out. Results Characteristics of wounded persons in nuclear and radiation accidents were clarified, and the classification principle, labeling and Methods were initially proposed. Conclusion The triage method would play an active role in scientific classification and orderly rescue for wounded persons in nuclear and radiation accidents.
  • ZHANG Peng-cheng, CAO Yong-zhen, YU Cheng-cheng, JIANG En-hai
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    Objective To study the protective effects of keratinocyte growth factor (KGF) and granulocyte colonystimulating factor (G-CSF) on hematopoietic system and important organs in irradiated mice. Methods 70 6-to 8-week old C57BL/6 mice were chosen as the objects on of study. They were randomly divided into 5 groups:the control group, irradiation group, KGF group, G-CSF group and the KGF plus G-CSF group, administered respectively after the 137Cs-gamma ray whole body irradiation. By detecting the body weight, organ index, organ SOD activity, MDA content, peripheral blood (WBC, RBC, Hb, PLT), the effect of KGF and G-CSF on irradiated mice blood and major organs were analyzed. Results After irradiation, the weight of KGF group and G-CSF group picked up more clearly; Compared with G-CSF group, there was statistically significant difference in lung index combined group (P < 0.05); Content index of peripheral blood RBC, Hb, PLT, combined group was higher than that of the other group; liver, heart SOD activity in G-CSF group is higher than that of KGF group and combined group, lung SOD activity in KGF group is higher than that of G-CSF group and combined group. Conclusion This study shows that of the mice hematopoietic system restoration in the combined is better than that of the other groups:G-CSF is more effective for the liver and heart antioxidant capacity; KGF is more effective for pulmonary antioxidant capacity.
  • ZHOU Yuan-yuan, YANG Chun-yong, WANG Fu-ru, DU Xiang, CHEN Wei, WANG Jin, YU Ning-le, SU Xu
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    Objective To study the X-ray radiation levels of medical accelerator room under different irradiation conditions. Methods In accordance with the standard 《The specification of radiological protection assessment for occupational hazard in construction project Part 2:Radiotherapy facility》 GBZ/T 220.2-2009,using the 451B ionization chamber X γ dose rate meter with the 10MeV accelerator as research object, the research object are divided into two groups,module group and blank group, measuring the radiation dose rate of shield walls and protective doors respectively when the accelerator's rack angle changes in four different gantry angles (0°, 90°, 180°, 270°), analyzing the Results. Results When the angle is 90°, the X-ray dose rate outside the west wall is higher than the other angle. When 270°, the X-ray dose rate outside the east wall is higher than others, and the dose rate outside the protective door is highest in the 270°. The module group's dose rate outside the protective door is 1.5 times higher than blank group. Conclusion The X-ray radiation dose level surrounding the accelerator room walls and protective door changes while the accelerator's rack angle changes differently. When detecting the doors'radiation level, the module should be set.
  • ZHAO Xin-Chun, ZHOU Yan, CHEN Zhang-Fan, ZHANG Hui-Min, XIE Ping, SU Xu
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    Objective To seek simple and reliable optimization calculation method for the radiation shielding thickness of the therapeutic room door of medical accelerator. Methods To calculate radiation shielding thickness of the therapeutic room door of a 15 MV medical accelerator by using simple method and the IAEA Safety Report Series No. 47 method. Results According to the national standard dose limit, Using IAEA 47 report accounting machine door shield thickness for nominal energy ≥ 10 MV accelerator,the total shielding thickness of Gamma ray and leak radiation is greater than that obtained by simple method, but the neuron shielding thickness value is not always greater. For nominal energy < 10 MV accelerator (No shielding neutron),the neuron shielding thickness value is not always greater than that obtained by simple method. Conclusion Because of the complex calculation, many parameters and data (not always accurate) are used; the calculation is easy to make booboo. Thus, we use two Methods to calculate and select a greater value of them to design. The Results show that the radiation shielding is feasible to meet the requirements of national standard in the subsequent accelerator workplace protection acceptance testing.
  • PENG Bang-bao, YAN Qiang, LI Tao-sheng, AN Dong, ZHANG Cheng-gong, ZHANG Peng-fei
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    Objective Radio-nuclides contents in soil of the Northeast China were measured. Based on the Results, the relationship between the radio-nuclides contents of different soil samples and some impact factors, such as the local climate, the source rocks, vegetation distribution, the degree of radioactive contamination and so on, was investigated. And the estimated value of annual effective dose was obtained. Methods Using NaI(TI) detectors, the radio-nuclides contents of standard soil sample, provided by the National Institute of Metrology of R. P. China, was measured to determine the efficiency (defined at full-energy-peak) of gamma-rays with the biggest branching ratio which were emitted from the radio-nuclides of 232Th、226Ra、238U and 40K. By analyzing the energy spectrum obtained by NaI(TI) detectors, the contents of radio-nuclides in soil samples were calculated out. Results By measuring the radioactivity of radio-nuclides in 26 soil samples from different zones of Northeast China, the radio-nuclides contents were calculated. The Results indicated that the contents, namely 52.9 Bq/kg for 232Th, 44.8 Bq/kg for 226Ra, 50.3 Bq/kg for 238U, 820.3 Bq/kg for 40K, increased slightly compared with the data obtained in past years. Conclusion The Results showed that the contents of 232Th had a maximum in residual-parent-material soils and minimum in deposit-parent-material soils, the contents of 236Ra and 238U had a maximum in alluvial-parent-material soils and minimum in residual-parent-material soils and the contents of 40K had a maximum in deposit-parent-material soils and minimum in alluvial-parent-material soils. As for the terrain, the contents of 232Th and 40K in soil samples from the plain land was smaller than sample from the mountain land, while the contents of 226Ra and 238U were the contrary. Theoretical calculation using the contents of Radio-nuclides in soils from different zones of Northeast China was carried and the estimated value of annual effective dose was obtained. With a value of 0.54 mSv/a, the calculated annual effective dose was in the normal range.
  • WANG Qing-rong, HE Ying, SHEN Xian-rong, JIANG Ding-wen, LI Ke-xian, LIU Yu-ming, QIAN Tian-tian, CHEN Wei, WANG Yan
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    Objective To investigate the radioprotective effects of sodium borocaptate on acute radiation-injured mice. Methods BSH was administrated in peritoneal injection with 0.2 ml/20 g. Mice were exposed wholely to 60Co γ-ray with the dose of 6 Gy (0.8 Gy/min). The count of peripheral blood cells was detected at 3rd, 14th day after irradiation. Organ index was detected at 14th day after irradiation. Results Compared to model control group, PLT of BSH (80 mg/kg) group increased significantly (P < 0.05) at 3rd day after irradiation, PLT, spleen index and thymus index increased significantly (P < 0.01, P < 0.05) at 14th day after irradiation. Conclusion The Results showed that BSH had protective effects on PLT and immune system of acute radiation-injured mice.
  • LIN Da-feng, ZHOU Jin-peng, WU Zi-jun, HUANG Xian-qing
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    Objective We explored the effect of low-dose nuclear radiation exposure, obesity, and abdominal obesity on complete blood counts in the nuclear power workers. Methods We collected information of health check-ups from 1 388 active workers in a nuclear power station, and determined their peripheral white blood cells (WBC) and each category, red blood cells (RBC), and platelets (PLT) counts. Obesity and abdominal obesity were defined as body-mass index of 30 kg/m2 or greater and waist circumference of 90 cm or greater in men, respectively. Results Longer working year as a nuclear power worker was the independent risk factor for increased counts of WBC and decreased percentage of monocytes, obesity was the independent risk factor for increased counts of WBC, and abdominal obesity was the independent risk factor for increased counts of WBC, RBC, and PLT, and decreased percentage of basophils (all P < 0.05). After stratifying by working years, obese workers of 1-9 years and abdominally obese workers of 1-9 and 10-19 years had higher counts of WBC than those of the non-obese and non-abdominally-obese workers in the corresponding working year groups, respectively (all P < 0.01). Conclusion Long-term exposure to low-dose nuclear radiation was associated with increased peripheral WBC counts in the nuclear power workers, which might be exacerbated by obesity or abdominal obesity.
  • YAN Yu-jun, XU Wen-qing, SHEN Xiu, WANG De-zhi, ZHAO Yun-ting, ZHOU Ze-wei
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    Objective To study the influence of a homogeneity polysaccharide A-BTF extracted from tremella fuciformis berk spores to chromosome aberration in cells of bone marrow of mice and micronucleus rate of polychromatic erythrocyte induced by 137Cs γ-ray irradiation. Mehtods Extracted polysaccharide of tremella fuciformis berk spores was administered by intra-abdominal injection at 24 hours before irradiation, and control mice were given physiological saline. The mice were irradiated by 137Cs γ-ray, then observed on chromosome aberration of bone marrow cells and micronucleus rate of polychromatic erythrocyte. Results The Results show that occurrence of chromosome aberration and micronucleus rate was obviously lower in mice administered prevention with polysaccharide than that of simply irradiated control mice, and with quite significant differece (P < 0.01). Conclusion It manifests that the homogeneity polysaccharide from tremella fuciformis berk spores is of marked protective effects for damages of bone marrow cells by irradiation.
  • TIAN Lei, LI Hui-cheng, CHI Qi, LU Xue, LIU Xiao-lan, WANG Tie-jun
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    Objective To compare the dosimetry distribution between conventional radiotherapy (CRT) and intensity modulated radiation therapy (IMRT) after breast-conserving surgery in early-stage breast cancer, and provide evidence for the application of IMRT in patients. Methods Twelve patients with early-stage breast cancer, who received breast conserving surgery, were selected in this study. CRT and IMRT plans with prescribed dose of 50 Gy/25 f were designed for each patient. The Dose volume histograms (DVHs) were used to evaluate the dosimetric distribution of the plan target volume (PTV) and the organs at risk (OARs) between the two plans. Results The V95% of PTV was similar in the two plans (98.22% vs 98.76%); The V105%、V110% of PTV in IMRT plans was 12.86%、1.02% versus 44.56%、6.37% in CRT plans(P < 0.05); The conformity index(CI) in IMRT plans was increased from 0.55 to 0.68, while the homogeneity index(HI) was decreased from 1.15 to 1.09(P < 0.05). Compared to CRT plans, the V30 and V20 of the ipsilateral lung in IMRT plans was reduced by 3.68% and 5.75%, the mean lung dose(MLD) was decreased from 9.24 Gy to 7.12 Gy(P < 0.05); In the left side patients, the V30、V40 and V50 of the heart in IMRT plans was reduced by 5.99%、5.68% and 1.68%, respectivly(P < 0.05). Conclusion Compared to CRT, IMRT decreased the high dose volume and improved the dose homogeneity with a satisfactory target coverage and effectively reduced the radiation dose for normal organs such as the heart and lungs.
  • CHEN Cheng, LIU Kai, JI Bo, WANG Ying-chao, LIU Ya-hui
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    Objective To investigate radiosensitization effect of valproic acid (VPA) on human hepatocellular cell line SMMC-7221 and its mechanism. Methods MTT was used to detect the proliferation and IC50 of SMMC-7221 cell. FCM was adopted to analyze the changes in cell cycle and apoptosis level. Results After co-cultured with VPA, the IC50 of SMMC-7221 cell was 41.26、9.04、2.87mmol/L. VPA + IR could significantly inhibit the cell proliferation, increase apoptosis level, cause G0/G1 phase arrest and decrease the decreased the percentages of S phrase. Conclusion VPA could enhance the cell-killing effect of SMMC-7221 cell as a radio-sensitizer, which was associated with apoptosis and cell cycle arrest
  • TANG Xiao-hao, REN Fu-li, PAN Shi-xiang, CAO Lei, DENG Jun
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    Objective The protective effect of medical accelerator room was analyzed, and shielding data were accumulated so as to provide the control of occupational exposure with scientific reference through in-site measurement and calculation with the existence of measuring phantom. Methods Radiation levels at concerned points were measured by X-ray dose rate meter with and without phantom, and accordance degree between the data measured and the one calculated based on NCRP 151 report was analyzed. Results The result shows that the X-ray dose level at the entrance of room and in the maze was increased with the use of phantom. Meanwhile, it shows strong link between scattered X-ray and radiation protection design of the maze and the orientation of X-rays. Conclusion Attention should be paid to the influence of measuring phantom on protective effect of treating room, and proper assessing model and method should be chosen to carry out the radioactive occupational hazard assessment for medical accelerator room.
  • JIANG Yan-hua, LU Wei, DONG Tian-xiang, CUI Geng
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    Objective To study the dose rate distribution for radiation device in operating room and safety measures of Protection for Radiation workers. Methods To be done through material investigation, experimental measurements, behavior observation and analysis of radiation workers. Results The radiation dose rate for mobile C-Arm X-ray Machnie attenuates by inverse distance of factor 2.278. Influenced by spatial layout, with the outside of protective screen area, the dose rate of the adjacent operating rooms and the corridors attenuates to background levels. The distribution of radiation dose rate in the operating room is affected by the horizontal, vertical direction of ray generator, thus affect the dose of the radiation workers received working in the operating room at different position. Conclusion Proper operation procedure of radiation devices with specified personal protection can effectively reduce the risk of radiation during operation for individual occupational health.
  • YANG Zhen-yu, LI Zhuan, SHEN Jin-chao
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    Objective To screen the imported food to see if it is polluted by the nuclear power plant leak. Methods Apply the excluding K gross β radioactivity method to detect the rice products and milk powders, test the recovery of Sr, Cs and calculate the LD. Results The Results of 12 imported rice products and 15 imported milk powders were lower than the LD. Conclusion Compare the GB Methods, the efficiency of this mothed is high. It needn't radiochemistry lab and fits for the screen test by CIQ lab.