Archive

  • 28 December 2002 Volume 11 Issue 4
      
  • Select all
    |
  • On Exemptions of Radioactivity from Regulatory Control
    ZHOU Shun-yuan
    2002, 11(4): 193-195.
    Download PDF ( ) HTML   Knowledge map   Save
    Objective To know well the exemption criteria and exemption levels of radioactivity from regulatory control.Methods It was done in accordance of the standards and other information on hand about exemptions of radioactivity.Results Some proposals for using exemption criteria and exemption standards are put forword.Conclusion It is imperative to understand and use precisely these proposals.
  • VEGF Expression during the Formation and Development of Radiation-Induced Skin Ulcers and Its Effects on Ulcer Healing: A Comparative Study with Normal Wound Healing
    GU Qing-yang, WANG De-wen, CUI Yu-fang, et al
    2002, 11(4): 196-197.
    Download PDF ( ) HTML   Knowledge map   Save
    Objective To study VEGF expression during the formation and development of radiation-induced skin ulcers and its effects on ulcer healing.Methods A rat model which was locally irradiated with 60Co γ-rays was used, and another rat model of simple skin wounds was made.Pathological changes were observed for 55 days.Immunohistochemistry, in situ hybridization and image analysis were performed to detect VEGF expression in the tissue of radiation skin ulcers and in the simple wounds.Results Skin ulcers were found on day 14 after irradiation, and they were enlarged and deepened gradually during the observation period.In the irradiated skin, especially in the epidermal cells, fibroblasts and endothelial cells in the ulcer beds, the expression of VEGF was higher than that in normal skin.But VEGF expression was obviously decreased in the radiation ulcer beds compared to that in the surgical wound beds.Conclusion After irradiation, the decreased expression of VEGF may play an important role in the formation, development and nonhealing mechanism of radiation skin ulcers.
  • Dosimetry of Dose Distribution in Normal Vessels Brought by Radioactive Solution in the Catheter for Intracoronary Restenosis Intra-balloon Brachytherapy
    XU Zhi-yong, ZHANG Liang-an, DAI Guang-fu, et al
    2002, 11(4): 198-199,201.
    Download PDF ( ) HTML   Knowledge map   Save
    Objective To estimate dose distribution in normal vessels delivered by radioactive solution in the catheter for intracoronary intra-balloon brachytherapy.Methods The dose distribution of normal tissue around balloon and catheter were estimated by the dose kernel function of Loevinger.Results The ratio of tissue around catheter to balloon was about 1/10.The average dose of blood around catheter and around vascular wall is 5.36 Gy, 1.62 Gy respectively.Conclusion The long-term and short-term effe cts would be considered when restenosis of intracoronary is treated with the method of radioactive balloon.
  • Determination and Assessment of Rn in Mineral Springs of Shandong Province
    XU Jia-ang, LI Fu-sheng, CHEN Ying-min, et al
    2002, 11(4): 200-201.
    Download PDF ( ) HTML   Knowledge map   Save
    Objective The concentrations and its changes of 222Rn in mineral springs of Shandong were determined in order to evaluate the committed equivalent dose for people drinking the water.Methods Scintillation flask method is used for the measurment of 222Rn concentrations in mineral springs.Results The concentrations of 222Rn in mineral springs of Shandong ranged from 0.51 Bq·L-1 to 807.20 Bq·L-1, the geometric average of it was 22.09 Bq·L-1.The relationship between the ratios of 222Rn remains in the water under the natural conditions (P) and the period of time exposed in air (T) was discovered, which is fits for the following function relation:P=46.666T-0.517 (0.117 h ≤ T ≤ 9 h).The committed equivalent dose resulting from 222 Rn concentrations was estimated to be 9.68×10-2 mSv·a-1, Which is due to drinking the water.Conclusion The analyses of data indicate that there is no over-burden dose from 222Rn for people who drink the water of mineral springs of Shandong.