The Inhibitory Effect of Extracts From Fructus lycii and Rhizoma polygonati on in vitro DNA Breakage by Alternariol

Alternariol caused DNA single-strand breakage. Conversion of the closed circular double-stranded supercoiled DNA (pBR 322) to the nicked circular form and linear form was used to investigate the effect of extracts of some Chinese medical herbs on DNA nicking induced by alternariol. Some substances in the extracts of Rhizoma polygonati (RP) and Fructus lycii (FL) were shown to protect DNA from the attack by alternariol.Some substance in the RP may bind to plasmid DNA, and this binding reduces the electrophoretic mobility of DNA. These results indicate that substances from FL and RP may be used as DNA protectors. It is possible that they play an important role in preventing cancer.

电梯导轨开裂原因分析

针对T89型电梯导轨开裂的问题,采用化学成分分析、氧氮分析、金相检验、扫描电镜观察和能谱分析等方法对开裂的电梯导轨进行解剖分析。结果表明,导致电梯导轨开裂的主要原因是连铸坯低倍质量差,含氧量、含氮量较高和振痕等缺陷,并对如何防止该类连铸坯开裂,提高产品合格率提出了建议。