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  • 28 March 2006 Volume 15 Issue 1
      

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  • WANG Qin, YUE Jing-yin, LI Jin, et al
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    Objective To investigate the role of XRCC repair genes in radioresistance of IRM-2 inbred mice.Methods Northern hybridization was used to measure mRNA expression of XRCC1 and XRCC5 genes in IRM-2 mice and their parental mice ICR/JCL and 615 after exposure to different doses of γ-ray radiation at different postirradiation time.Results The levels of XRCC1 and XRCC5 mRNA expression in control IRM-2 mice were higher significantly than those in their control parental mice (P<0.01 and P<0.05).The mRNA expression of XRCC genes in ICR/JCL and 615 mice all increased to some extent after exposure 1, 2 and 4Gy radiation.But the levels were significantly higher at 2h postirradiation (P<0.05).The levels of XRCC mRNA expression in IRM-2 mice did not increase significantly compared with the control mice after exposure 1 and 2Gy radiation.But the levels of XRCC1 and XRCC5 mRNA expression increased markedly at 4Gy 1h postirradiation (P<0.05 and P<0.01).Conclusion The basal levels of XRCC1 and XRCC5 mRNA expression in IRM-2 mice were high.The high level of XRCC5 mRNA expression was involved in the repair of DNA double strand breaks induced by higher dose radiation, which perhaps was one of radioresistance causes of IRM-2 mice.
  • WANG Yue-xing, LU Yong-jie, YANG Yi-fang, et al
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    Objective To prepare whole body average absorbed dose, FD (E), per unit neutron fluence for energy E which can be used for neutron dose assessment in a nuclear accident or neutron exposure accident.Methods In accordance with absorbed dose per unit neutron fluence of various organs and tissues for monoenergetic neutrons incident in various geometries on adult anthropomorphic computational model by ICRP Publication 74, the qualities weighting of 5 bigger principle organs or tissues (red bone marrow, liver, lungs, stomach and colon) of Chinese reference man were applied to calculation of FD (E).Results The FD (E) of various neutron energies E and FDCf/FDU weighted by 252Cf/235U fission neutron spectrum have been calculated.Conclusion If once neutron spectrum and fluence incident on human body in a accident are determined, using FD (E) the receiving absorbed dose of entire body of the patient can conveniently be calculated.
  • WANG Yue-ying, ZHOU Ze-wei, WANG Ru-qin, et al
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    Objective To examine the therapeutic results of E838 for the cervical carcinoma (U14) and lung Adenocarcinoma (LA795).Methods The tumor cells of U14 and LA795 were transplanted subcutaneously into the IRM-2 mice.The bearing tumor mice were administrated ip with doses at 5 mg/kg、7.5 mg/kg、10 mg/kg of E838, then the changes of body weight of mice, tumor growth nucleated cells of bone marrow (BMC), weights of spleen and thymuses were determined.Results The Inhibition rate of tumor growth for doses at 5 mg/kg、7.5 mg/kg、10 mg/kg a animal were 36.8%、64.3%、49.7% for U14 and 46%、60%、58% for LA795.The BMC in the both mice bearing U14 and LA795 groups were higher than that in control groups.Conclusion These results Indicate that E838 have the significant tumor Inhibition effects in vivo in the inice bearing U14 and LA795 and have stimulation function in the bone marrow cell multiplication.
  • TIAN Yi-zong, GAO Jian-zheng, LIU Wen-hong
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    Objective By imitating experiment of radioactive sources being installed, to estimate the annual whole-body exposure dose of radiation workers of petroleum nuclear determining wells;Methods To compre the values of the theory, imitating experiment and γ individual dose monitor calculations.Results The three values measured above tally with one anather.Conclusion The annual whole-body exposure doses of radiation workers of petroleum nuclear determining wells are no more than 5mSv.
  • LIU Chang-an, KONG Qing-jun, CHEN Er-dong, et al
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    Objective To develop software for estimating skin dose from X ray, gamma ray, neutron, and especially β ray external exposure.Methods Based on International Commission on Radiation Units and Measurements (ICRU) Report 56 and relevant Chinese standards, a software was developed with Vc++6.0 program and Access database to computerized the methods of skin dose estimation.Results The skin dose from β、X、β ray and neutron could be estimated rapidly and approximately with the present software.In addition, this program archives detailed information of affected individuals for later use in consultations and analyses.Conclusion The calculating speed and precision of skin dose estimation is improved by this software, which would appear to be a rapid and useful early triage instrument in nuclear and radiological emergency circumstances.
  • WANG Xiao-feng, BAI Mei, SUN Xue-mei, et al
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    Objective Percutaneous coronary interventions are associated with increased radiation exposure compared to most of the radiological examinations.This prospective study aimed at personnel dosimetry research of CA and PTCA, guided by the theory of radiation optimization.Methods The staffs dose was recorded by TLD, while the protective effect was surveyed by the portable dosimeter.Results 1.Having doses measured on the key parts of operator's body, and computing their effective dose by models.Effective dose per procedure was estimated to be 3.5μ Sv for the principal operator.2.Having measured and judged the system of radiation protection of interventional radiology.3.Having estimated the risk for fatal cancer to operators conduced by intervention radiology.Lifetime probability of fatal cancer was 3.5×10-8 and 4.9×10-9 for the principal operator and assistant operator per procedure.Conclusion Regarding radiation exposure, coronary intervention is considered a quite safe procedure for personnel in laboratories with modern equipment and experienced operators as long as standard safety precautions are considered.Exposure optimization though should be constantly sought through continuous review of procedures.
  • ZHAO Guo-Liang, LUO Cheng-Ji, XU Xiang-Yu
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    Objective To find out infection of professional radiation on radioactive working personnel, and offer pertinence advise and gist for constituting radioactive protection measure.Methods through epidemiological diagnoses, observe, study and analyse three radiation sensitivity parameters of 912 people.Results ophthalmological abnormity rate increase along with length of service;outer hemogram and chromosome aberration rate does not increase along with the length of service all the time, but drops from 15a.Conclution there is a certain infection of professional radiation on the health of working personnel, and we can constitute to take more logical protective measure.
  • LIU Peng-cheng, DU Duan-ming, CHEN Zai-zhong, et al
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    Objective To study the 3-dimension radiation protection methods in interventional radiology and evaluate its clinical value.Methods Lead sheild, shade, clothes, scarf, glass and distance were used to protect radiation.RAD-60S personal dosimeter were used to detect the dose of X-ray radiation.Results Lead shield, shade, clothes and longer distance can obviously reduce the dose of X-ray radiation.The dose of X-ray radiation is correlated with the continuance time of fluoroscopy and subtraction.The longer the time, the more the dose of X-ray radiation.Conclusion The 3-dimension radiation protection methods in interventional radiology can reduce the dose of X-ray radiation and protect doctors and patients.
  • CHEN Ying-min, LI Fu-sheng, XU Jia-ang, et al
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    Objective To study the natural radioactive nuclide distribution characteristic of fly ash, gangue and various kinds of slag used in the new-type wall material and offer scientific basis for reducing the radiation dosage that the public suffers.Methods The activity concentrations of the content of natural radioactive nuclide of different industry waste residue have been deter-mined by HPGe gamma-ray spectrometry.Results The mean Raeq is successively fly ash (279.13 Bq kg-1), slag (225.69 Bq kg-1), gangue (141.26 Bq kg-1) from high to low and all of the samples is lower than the limit set in the OECD.The arithmetic mean activities of 226Ra、232Th、40K in fly-ash samples are 127.88, 93.83, 221.75 Bq kg-1;for coal slag samples are 73.89, 97.13, 293.44 Bq kg-1 and for coal gangue samples are 47.85, 45.21, 413.56 Bq kg-1.For the same power plant, the radioactive nuclide activity of the fly ash gathered in different time may have very great differences, the maximum can reach more than 2 times of the min-imum.Conclusion The fly ash and slag should be controlled strictly on rational proportion, which should not exceed 70% of the to-tal mass.The mixing of the average radioactive level of the gangue is nearly equal that of to clay, it can be unrestricted in the mixing proportion in process of production.The manufacturer of new-type wall materials should often measure the radioactive level of the in-dustrial waste residue in production.Make the content of radioactive nuclide in the products reach the rational level as low as possible
  • WU Zi-xing, LIU Yan-bin, JIA Yu-xin, et al
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    Objective To explore relevant factors about the soil radon measurement and provide gist of formulating correct measure method by studying the way of the soil radon measurement.Methods Deflation-ionization room standard is adopted.Results The concentration of soil radon becomes higher with the sample's volume added, it also augmented with the measure depth increased in certain degree;The concentration of soil radon changes little when sample's depth is above 60cm;The time of deflation has no obvious influence on the concentration of soil radon, but microwave show serious effect on it;The results will be lowered when the desiccant is humidified, raining has the same affection on it;Plant has some impact on it.Conclusion The measured results will be affected by microwave, oscillate and plant.Sample's volume and depth, soil's humidity can influence it too.The result's veracity can be guaranteed by choosing appropriate sample and measure condition.
  • WEN Zun-bei, SU De-qing, LIANG Yu-xue
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    Objective To investigate pathogen dose existing or not in patients with radiation mucositis.Methods From Juanary 2004 to August 2005, from 46 patients with radiation mucositis some pharynx secretion were taken for culture.then they were treated with antibiotics selected by the cultured results and gargle.Results 5 patients with grade 0 of radiation mucositis were with no cultured pathogen, and the results of some other patients with radiation mucositis include 8 cases of epiphyte, 1 cases of p.vulgaris and 3 cases of Staphylococcus, The positive rate is 29.2%(12/41);Conclusion Some patients with radiation mucositis do exist pathogen, and we must slect antibiotics by the bacterial cultured results.
  • XU Hai-rong
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    Objective To investigate the feasibility of checking the dose distribution of radiosurgical treatment of X knife for brain tumour by LiF (Mg, Cu, P) CR-200A TLD and the tissue equivalent head phantom.Methods The tissue equivalent head phantom was cut into four slice.with taking of the second and the third slice being chosen to be used.Small holes (Φ1×0.5 cm) were drilled at the interesting organs on each segment.The TLD (Φ1×0.5 cm) were placed in the holes.The doses to each measuring position were calculated out.After the treatment plan was delivered the does to each TLD were measured by dosimeter.Measuring the dose distribution in phantom for head using TLD and film dosimeter is to verify the does for clinical practice.Results The relative errors for those TLD are within ±5%.The relative errors for those films are within ±3%.Conclusion The LiF (Mg, Cu, P) CR-200ATLD, film dosimeter are accurate and reliable in checking the dose distribution of radiosurgical treament of Jx-100x knife for brain tumour.