LY12CZ铝合金飞机内外部结构涂层日历有效性试验研究

基于外部和内部涂层加速试验环境谱,分别对某型飞机的LY12CZ铝合金内、外部结构涂层进行加速老化试验,统计分析了两种涂层腐蚀老化表面形貌,得到了光泽度和色差随加速腐蚀时间的变化规律,并对涂层的有效性进行了综合评定。试验结果表明,LY12CZ铝合金外部结构涂层的有效期为12 a,内部结构涂层的有效期为10 a,轻微划痕对外部结构涂层的日历有效性影响不大,而对内部结构涂层有一定影响。     

农药氰戊菊酯和三氟氯氰菊酯对蚕豆根尖细胞的遗传损伤

采用蚕豆根尖微核技术研究了农药氰戊菊酯、三氟氯氰菊酯对蚕豆根尖细胞的遗传损伤.测定了不同浓度氰戊菊酯、三氟氯氰菊酯(5×10-10～5×10-2g·L-1)诱导下的蚕豆根尖细胞微核率、有丝分裂指数和染色体畸变率.结果表明,氰戊菊酯、三氟氯氰菊酯均能诱发较高的微核率,在一定浓度范围内,微核率随两种农药处理浓度的升高而增加,但随着处理浓度的进一步升高微核率反而呈下降趋势;两种农药均可使蚕豆根尖细胞有丝分裂指数增大;并能诱导蚕豆根尖细胞产生较高频率、多种类型的染色体畸变.氰戊菊酯和三氟氯氰菊酯对蚕豆根尖细胞具有明显的遗传毒性.     

Genotoxic effects of Bismuth (III) oxide nanoparticles by Allium and Comet assay

Genotoxic effects of Bismuth (III) oxide nanoparticles (BONPs) were investigated on the root cells of Allium cepa by Allium and Comet assay. A. cepa roots were treated with the aqueous dispersions of BONPs at five different concentrations (12.5, 25, 50, 75, and 100 ppm) for 4 h. Exposure of BONPs significantly increased mitotic index (MI) except 12.5 ppm, total chromosomal aberrations (CAs) in Allium test. While stickiness chromosome laggards, disturbed anaphase–telophase and anaphase bridges were observed in anaphase–telophase cells, pro-metaphase and c-metaphase in other cells. A significant increase in DNA damage was also observed at all concentrations of BONPs except 12.5 ppm by Comet assay. The results were also analyzed statistically by using SPSS for Windows; Duncan’s multiple range test was performed. These results indicate that BONPs exhibit genotoxic activity in A. cepa root meristematic cells.     

农药乙蒜素和细菌溴腈对蚕豆根尖细胞的致畸效应

利用蚕豆根尖微核技术研究农药乙蒜素和细菌溴腈对蚕豆根尖细胞的遗传损伤,测定蚕豆根尖细胞的微核率、有丝分裂指数和染色体畸变率.结果表明:2种农药均能诱发较高频率的微核率、有丝分裂指数和染色体畸变率.在乙蒜素质量浓度为0.032～0.160 g·L-1范围内,微核率随浓度升高而升高,呈一定的剂量-效应关系(r=0.881 9,P≤0.01);而在细菌溴腈质量浓度为0.625～2.5 g·L-1范围内,微核率则呈先上升后下降的趋势.     

Cytogenetic prenatal diagnosis and its relative effectiveness in the mersey region and North Wales

The relative effectiveness of cytogenetic prenatal diagnosis in the Mersey Region and North Wales is presented by estimating the percentage detection rates of Down's syndrome annually following amniocentesis from 1978–1984 inclusive. Tables indicating the percentage of screened pregnancies, types of chromosomal aberrations detected and the occurrence of Down's syndrome in mothers in age groups of five-year intervals are also presented. The average prenatal detection rate for Down's syndrome (estimated at the time of birth) was 15–15 per cent over the years 1978–1984 and was above 22 per cent for the last two years when 44–13 per cent of all pregnancies to mothers of 35 years and over were investigated.     

一种水质污染生物监测的新方法——蝌蚪肠细胞染色体畸变分析

发展了一种水生脊椎动物蝌蚪肠细胞染色体畸变的分析方法,可作为诱变剂污染水源的早期报警系统。该方法的优点:1)灵敏度高;2)蝌蚪在我国分布广、数量多、捕捉方便、费用低、易饲养管理。尤其是蝌蚪的核型由22条大的中部和亚中部着丝点染色体所组成,适于毒理遗传学研究;3)蝌蚪具有转化前诱变剂或前致癌剂为活性成份的微粒体活化系统。     

镉对洋葱根生长和细胞分裂的影响

研究了不同浓度氯化镉溶液对洋葱根的生长,细胞分裂和染色体形态的影响.结果表明,随Cd~(2+)浓度增加,根的生长速率递减;随处理时间延长,每单位时间的根生长速度递减或停止,根尖细胞有丝分裂指数随Cd~(2+)的浓度增高和处理时间延长而递减.不同浓度Cd~(2+)都能引起染色体畸变,恢复培养后均能恢复生长,染色体畸变率降低     

Abnormal karyotype in the chorion,not confirmed in a subsequently aborted fetus

An abnormal fetal karyotype, containing a del 16(q21-qter) as an extra chromosome, was diagnosed in all 14 metaphases examined in a sample of chorionic villous biopsy material. After elective abortion a mosaicism for this cell-line together with a normal one was detected in the chorionic tissue. Fibroblast cultures from several fetal skin biopsies all revealed a normal karyotype.     

砷细胞遗传毒理学研究的最近进展

本文对砷细胞遗传毒理学研究的最近进展进行了简要评述。着重介绍了砷对人体，试验动物及某些植物诱发染色体畸变，姊妹染色单体互换及微核的效应；对砷诱发体外培养的人类细胞和试验动物细胞染色体畸变，姊妹染色单体互换及微核效应也作了介绍。