Objective:Using Monte Carlo simulation method to study the important dosimetric parameter output factor of the LUNA stereotactic body radiotherapy device. Methods:Following the manufacturer’s technical documentation to establish the LUNA stereotactic body radiotherapy device’s Monte Carlo model and after model validation. After referring to the output factor measurement’s detector provided by manufacturer, set the relevant parameters in Monte Carlo model at last, compare and analyze the difference of output factor which provided between by manufacturer and calculated by Monte Carlo simulation. Results:In the range of 3%deviation, under the different collimator of condition, output factors which provided by manufacturers and calculated by Monte Carlo are in good agreement, and the reasons for the difference are also analyzed. Conclusion:LUNA stereotactic body radiotherapy device’s output factors of Monte Carlo simulated research work provides reference and basis for the clinical use and quality control.

Objective To study the quality testing of dose delivery system of the active spot scanning proton and heavy ion accelerator,in order to provide the reference for the quality control of related equipment.Methods In the four therapy rooms,both 0.6 cc chambers and Gafchromic EBT3 films were used,respectively,to test the accelerator for dose reproducibility,dose linearity,dose stability,depth dose distribution,beam scanning position deviation and radiation field uniformity in each therapy room.Results Dose reproducibility variation coefficients are all less than 1.5％,dose linearity's maximum deviations less than 2％,dose stability's deviations less than 2％,depth dose distribution stability within 2％,beam scanning position deviation less than 1 mm,consistency of irradiation field's deviation less than 2 mm,and flatness within ± 5％.Conclusions The indicators about quality testing for the active spot scanning proton and heavy ion accelerator are all in line with the requirements of IEC standards draft.

Objective To develop the method for testing the consistency of irradiation field produced by the active spot scanning proton and heavy ion accelerator.Methods Calibration of the EBT3 films were carried out with the calibrated ion beam to establish the dose calibration curve.According to the different proton and carbon ion energies (proton:94.29,150.68,212.62 McV;carbon ion:175.99,283.43,412.54 MeV/u),EBT3 films were located in the solid water phantoms in each therapy room,respectively.Finally,the irradiated EBT3 films were scanned and the radiation field size's deviation and flatness were analyzed.Results In different conditions,radiation field size's deviations were all less than 2 mm and the flatness parameters were all controlled below the 5％.Conclusions EBT3 films can be used to test the active spot scanning proton and heavy ion accelerator's radiation field uniformity.

Objective To facilitate activity measurement by using the thimble ionization chamber in hospitals,to obtain air kerma scatter correction factor of medical afterloading of 192Ir source by developing an available and convenient calculation method.Methods According to International Atomic Energy Agency (IAEA) 1079 Report to calculate the scatter correction factor of 192 Ir source,to measure air kenna of 192Ir source with and without lead shield using thimble ionization chamber.Simulation measurement conditions were used to calculate scatter correction factor of 192Ir source and comparison was made between experimental results and literature records.At the same time,the different ionization chamber models were simulated at different room sizes to obtain scattering correction factor of 192 Ir source.ResultsComparison was made between the simulation scatter correction factors of 192Ir source and experiment by the shadow shield,and the relative deviation was 0.8%.The deviation of the 192 Ir activity calculated according to the simulated scatter correction factor and measured by well type ionization chamber was 2.4%.By comparison between the calculated results by using two kinds of spherical ionization chamber and those ones deduced by IAEA 1079 Report,the relative deviations ranged within 0.3%-0.4%.Five different types of thimble ionization chamber and different room sizes were simulated and calculated by MC simulation,with the relative deviation within 3%.Conclusions Monte Carlo simulation method for calculating afterloading 192 Ir source's scatter correction factor is feasible,and this method is convenient for use in the thimble chamber for brachytherapy QA work in the hospital.

Objective To explore the method for measuring and calculating both absorbed dose and effective dose received in organ and tissues of occupational workers by using TLDs for the implantation of 125Ⅰ seed sources.Methods The experiments with 60Co γ-rays were carried out for the stability.A group of TLD chips was exposed to 125Ⅰ seed sources to establish standard dose curve for air kerma.During the 125Ⅰ seed implantation, the TLD chips were pasted to 13 locations like thyroid inside and outside the lead aprons worn by occupational workers to measure average absorbed dose and calculate the absorbed doses and effectives to organs and tissues.Results For 3 cases of prostate cancers with implantation of 125Ⅰ seeds, the worker's organs and tissues received the absorbed dose 0.02 -3.80 μ Gy and effective dose 0.06- 1.81 μSv outside lead aprons and the highest absorbed dose 2.35 μ Gy and effective 0.02 μSv inside lead aprons, respectively, with more than 65.9% of rays shielded.For 3 cases of brain cancers with implantation of 125Ⅰ seeds, the workers received the absorbed dose 0.23 - 11.31 μGy and effective dose 0.88 - 4.07 μSv outside lead aprons and the highest absorbed dose 2.22 μ Gy and effective dose 0.09 μSv inside lead aprons, respectively, with more than 54.5% of rays shielded.For 3 cases of lung cancers with implantation of 125Ⅰ seeds, the workers received the absorbed dose 0.03 - 14.78 μGy and effective dose 0.35 -7.59 μSv outside lead aprons and the highest absorbed dose 4.09 μGy and effective 0.22 μSv inside lead aprons, respectively, with more than 58.4% of rays shielded.For 2 cases of mediastinum cancers with implantation of 125Ⅰseeds, the workers received the absorbed dose 0.06 - 74.91 μGy and effective dose 0.83 - 17.96 μSv outside lead aprons and the highest absorbed dose 10.29 μGy and effective 0.5 μSv inside lead aprons, respectively, with more than 85% of rays shielded.For one case of ovary cancer with implantation of 125Ⅰ seeds, the worker received the absorbed dose 0.09 - 14.29 μGy and effective dose 2.40 - 4.50 μSv outside lead aprons and the highest absorbed dose 7.77 μGy and effective 0.12 μSv inside lead aprons, respectively, with more than 34% of rays shielded.For one case of eye cancer with implantation of 125Ⅰ seeds, the workers received the absorbed dose 2.2 -39.84 μGy and effective dose 4.48 - 10.06 μSv outside aprons and the highest absorbed dose 5.19 μGy and effective 0.16 μSv inside aprons, respectively, with more than 54.6 % of rays shielded.Conclusions The method of using TLDs to measure the doses to the occupational workers in the course of the implantation of 125Ⅰ seed sources is simple and easy to operate.It would be an effective approach to protecting medical workers in the case of brachytherapy.

Objective To explore the possibility of heterogenous gene to express in juvenile Schistosoma japonicum and the application of electroporation in transformation of schistosomulae. Methods The plasmids of pEGFP-C1 were introduced into mechanically transformed schsitosomula with electroporation. The presence, transcription and translation of the transgene in electroporated schistosomula were confirmed by PCR, RT-PCR and Western blotting analysis respectively using the genomic DNA, total RNA and protein extracted and isolated from schistosomula cultured in vitro for 48 hours. Meanwhile, localization of EGFP within electroporated schistosomula was performed with confocal laser scanning microscope. Results 760 bp and 276 bp amplified products by PCR and RT-PCR were found coincident with the expected size and expression of EGFP gene in elctroporated schistosomula was confirmed by Western blotting. Fluorescence of EGFP was localized in tegument and subtegument of the electroporated schistosomula with confocal microscopy, especially in the anterior part of the worm. Conclusion The heterogenous gene of EGFP has been successfully introduced into juvenile S. japonicum by electroporation and the expression of transgene was confirmed with molecular and microscopical methods.

Objective To evaluate clinical value of denaturing high performance liquid chromatography (DHPLC) used in detecting transforming growth factor beta receptor 3 (TGFBR-3) exons 11 and 12 polymorphism in women with idiopathic premature ovarian failure (POF).Methods From Feb.2009 to Dec.2011,110 patients with idiopathic POF undergoing treatment at Shenzhen Maternal & Child Health Institute affiliated to Southern Medical University were enrolled as POF group in this study.In the mean time,110 women under 40 years old with normal hormonal level and menstrual cycles as control group.The exons 11 and 12 of TGFBR-3 gene polymorphism were screened by using DHPLC,and results of DNA sequencing was as golden standard.Some related indexes were calculated,such as sensitivity,specificity,false negative value,false positive value,Youden index,positive predictive value,and negative predictive value.At the same time,20％ of the tested specimens were chosen randomly and detected by DHPLC again.The value of Kappa index were calculated by comparing the results between the first and second DHPLC analysis.Results The exon 11 of TGFBR-3 were not identified gene polymorphism and two nucleotide polymorphisms were identified in exon 12.For 2022 T/C polymorphism,the frequencies of CC with 0.9％ (1/110),TC with 22.7％ (25/110),TT with 76.4％ (84/110),Cwith12.3％ (27/220) and T with 87.7％ (193/220) in POF group were significantly different from CC with 0,TC with 9.1％ (10/110)and TT with 90.9％ (100/110),C with 4.5％ (10/220) and T with 95.5％ (210/220) in control group (all P ＜ 0.05).Allelic and genotypic frequencies of 2161-75 C/T were not differed significantly between the two groups (all P ＞ 0.05).As DNA sequencing as golden standard,DHPLC showed that the sensitivity was 100％,specificity was 97.9％,Youden index was 97.9％,positive predictive value was 96.3％,negative predictive value was 100％,and Kappa index was 0.888 (P ＜ 0.05).Conclusion DHPLC analysis is higher validity,reliability and practicability method in detecting TGFBR-3 polymorphism in idiopathic premature ovarian failure.

Aim To observe the effect of astragalosides on proliferation and collagen synthesis of HSC-T6 cells driven using schistosoma japonicum soluble egg antigen-activated macrophage conditioned medium(SEA-MCM).Methods SEA-MCM was prepared by injection of Schistosoma japonicum SEA via mice peritoneal.The proliferation and collagen synthesis of HSC-T6 cells stimulated with SEA-MCM were measured using MTT colorimetric assay and()~3H-proline incorporation respectively.Results The proliferation and collagen production of HSC-T6 cells were significantly promoted by SEA-MCM.They were significantly suppressed after being treated with AST(32.5、65、130 mg?L~(-1)) showing concentration-dependent effect.Conclusion:Astragalosides may inhibit HSC-T6 cells proliferation and collagen production that was driven by SEA activated MCM in vitro.

Objective To verify the reliability of dose parameters of radiotherapy under reference and non-reference conditions by using TLD.Methods Dose parameters were verified by using TLDs under reference and non-reference conditions,including the maximum dose in axel of 5 electron beams with energy of 9 MeV and the variations of dose by depth,source-skin distance,exposure field and 45° wedge for 10 photon beams with energy of 6 MV in 5 hospitals.Results The average relative deviation of 6 MV photon beam measured between TLDs and finger ionization chambers were 4.45％,within ± 7％ as required by IAEA.The average relative deviation of 9 MeV electron beam measured between TLDs and plane parallel chambers were 2.45％,within ± 5％ was required by IAEA.Conclusions Measuring dosimetric parameters by using TLDs under reference and non-reference conditions was reliable and feasible.