放射源断续照射受照者细胞遗传学观察及辐射影响评价

本文报道2002年某单位放射源事故中受照者及相关人员的细胞遗传学检测结果，并对受照剂量进行了估计。根据染色体双着丝点 环和微核结果结合临床资料，诊断受照者为亚急性轻(中)度放射病。52名相关受检者中有部分人员受到一定程度的射线照射。     

细胞遗传学技术在辐射生物剂量估算中的应用

细胞遗传学技术作为生物剂量测定方法,已在生物剂量估算特别是急性照射剂量估算方面得到广泛应用和验证。本文重点综述染色体畸变、微核、早熟染色体凝集作为生物剂量测定方法在剂量估算应用中的优缺点,扼要介绍近年来发展起来的一些分子生物学指标用作生物计量估算的进展。     

UV disinfection of indigenous aerobic spores: implications for UV reactor validation in unfiltered waters

Conventional validation testing of UV reactors use cultured microorganisms spiked into test water flowing through a reactor. These tests are limited by the microbe titer it is possible to grow, thus limiting the size of the reactor it is possible to validate. The goal of this study was to examine the UV inactivation of indigenous aerobic spores naturally occurring in raw/unfiltered water supplies and to assess their use as an alternative indicator for validation testing of UV reactor performance, specifically for unfiltered water supplies planning large UV reactors. These spores were found in all raw waters tested in concentrations ranging between 20 and 12,000 CFU/100 mL and were very resistant to UV irradiation compared to a range of different microbes in the literature (i.e. adenovirus, MS-2 coliphage, and Cryptosporidium parvum). The inactivation of indigenous natural aerobic spores followed first-order kinetics with an inactivation coefficient ranging between 0.013 and 0.022 cm2/mJ with a high correlation coefficient. It was determined that naturally occurring aerobic spores, well characterized with respect to UV 253.7 nm inactivation, can be a useful tool when validating plant performance, and might also be used as a regular monitor of UV fluence and performance in a water treatment plant.     

急性辐射损伤的生物剂量估算方法

探讨各种急性电离辐射损伤生物剂量估算方法的适用性。分析了各种辐射剂量估算方法的优缺点和应用潜力,根据每种生物剂量估算方法特点,给出其适用场合的建议。认为急性辐射损伤情况下快速剂量估算的适用方法为:体牙齿和指甲的ESR测量、全自动微核分析和全自动γ-H2AX分析。     

60 Coγ射线对人线粒体COXI和ATPase6表达水平的影响

目的：观察60 Co γ射线对人外周血线粒体COXI和ATPase6基因和蛋白质水平表达的影响,探讨线粒体编码基因用于辐射生物剂量估算的可行性。方法采用60 Coγ射线照射正常人离体外周血,照射剂量率为1．013 Gy/min ,剂量分别为0、0．2、0．4、0．6、0．8、1．0、2．0、3．0、4．0、5．0 Gy,。照后6小时,用RT-PCR技术检测基因的表达水平,用流式细胞仪检测蛋白质的表达水平,分别拟合最佳回归方程,建立剂量-效应曲线。结果（1）0～3．0 Gy ,COXI基因表达水平的最佳回归方程为 Y＝0．629＋0．256 D （ r2＝0．920,p＜0．01）,ATPase6基因表达水平的最佳回归方程为 Y＝0．221＋0．805 D （ r2＝0．912,p＜0．01）。（2）0～5．0 Gy ,COXI蛋白质表达水平的最佳回归方程为 Y＝1．054＋0．595 D （ r2＝0．919,p＜0．01）;ATPase6蛋白质表达水平与照射剂量间的关系不明显,不能拟合出最佳回归方程。结论60 Coγ射线照射人离体外周血,随着照射剂量的增加,线粒体COXI的基因与蛋白质表达水平一致,呈增加趋势,且有良好的线性关系,有望用于辐射生物剂量的估算。     

染色体易位率和辐照剂量关系的建立及应用

采用1#2、#、4#全染色体涂染探针联用的荧光原位杂交（FISH）技术,检测60Coγ射线诱发正常人染色体稳定性畸变的易位率,建立剂量-效应关系,拟合的最佳回归方程为Y=0.0132＋0.0757D＋0.0158D2。实际应用验证结果表明,在远期受照生物剂量估算中,该剂量-效应关系有良好的应用价值和应用前景。     

Disinfection of Drinking Water by UV Irradiation: Basic Principles - Specific Requirements - International Implementations

The quality control of UV drinking water disinfection has made an enormous progress in the last decade. The better understanding of the process and the higher quality assurance of the UV disinfection plants has increased the acceptance of UV drinking water disinfection. Three UV water disinfection standards were internationally developed by the USEPA, the German Association for Gas and Water and the Austrian Standards Institute. The quality assurance of safe UV water disinfection is based on 3 main prerequisites: the knowledge of the UV resistance of health related microorganisms transmittable by water, to set a sufficient high UV fluence, the careful evaluation of commercial UV plants and the control of the UV irradiation process during practical application by means of defined alarm points and a calibrated UV sensor, which allows checks against official specifications. Here we describe the basic principles of the validation of UV drinking water systems and point out the specific differences between the three international UV disinfection standards with regard to validation.     

EVALUATION OF UV DOSE IN FLOW-THROUGH REACTORS FOR FRESH APPLE JUICE AND CIDER

High absorptivity and turbidity interfere with the UV disinfection of apple cider. Three different configurations of flow-through UV reactors were evaluated to overcome this interference. Two approaches were employed: use of an extremely thin film UV reactor and increasing the turbulence within a UV reactor. Multiple-lamp UV reactors including the thin-film laminar flow “CiderSure” (8 lamps) and turbulent flow “Aquionics” (12 lamps) and annular single-lamp “UltraDynamics” reactor were studied. UV disinfection performance in laminar and turbulent flow reactors was compared by evaluation of UV dose delivery. UV fluence rate (irradiance) distribution was calculated using the multiple point source summation method. E. coli K12 was used as a target bacterium in a bioassay, and the log reduction per one pass was determined for each UV reactor. Finally, the UV decimal reduction dose (D₁₀) was calculated by dividing the average UV fluence by log bacterial reduction per pass. Variations of the UV decimal dose were observed with various designs of UV systems. The least inactivation of E. coli K12 but the highest UV decimal reduction dose, ranging from 90 to 150 mJ/cm², was observed in the Aquionics UV reactor in apple cider with apparent absorption coefficient (a) of 5.7 mm^?1. The lower value of UV decimal reduction dose of 7.3–7.8 mJ/cm² was required for inactivation of E. coli K12 in malate buffer and apple juice in the annular single-lamp UltraDynamics reactor. However, the decimal reduction dose for E. coli K12 in apple cider was significantly higher, about 20.4 mJ/cm². Similar UV decimal reduction doses from 25.1 to 18.8 mJ/cm² for inactivation of E. coli K12 were observed in the thin-film ‘CiderSure’ UV reactor in apple cider with identical absorption coefficient. Mathematical modeling of UV irradiance can improve the evaluation of UV dose delivery and distribution within the reactors.     

全球辐射应急生物剂量实验室网络系统

拟建立的全球辐射应急生物剂量实验室网络系统,能够运用多种手段进行辐射剂量估算。本文介绍了在辐射应急响应中,世界卫生组织、国际原子能机构与国际标准化组织在生物剂量国际合作方面发挥的作用和能够利用的资源;介绍了有关建立全球辐射应急生物剂量实验室网络系统的发展方向,以及WHO将要采取的措施。