生物节律因子的调光计算

针对光生物效应重要性及复杂性问题,提出一种生物节律因子的调光计算方法。给定三通道LED工作在额定条件下的光谱分布就能够实现任意比例的混合光源的照度、相关色温、节律因子的便捷计算。实验选用三种色温白光LED组成三通道光源,基于脉冲宽度调制(PWM)原理进行三通道分时调光。在某一照明测试空间距离下,先测得单通道独立工作时的光谱分布,并通过调光计算方法得到三通道在任意比例下混合光源的理论照度、相关色温、节律因子;再测得三通道光源在不同混合比例下的实际照度、相关色温与节律因子。然后将理论与实际计算所得的照度、相关色温、节律因子进行比较,并分析误差。实验结果表明,照度、相关色温、节律因子的多条拟合直线与调光计算式所描述直线的斜率差异分别在6%、2%、3%以下,截距差异分别在2%、5%、3%以下。用显著性差异检验来检验实际节律因子与理论计算所得节律因子的正态分布特性,结果显示并无明显差异,表明在给定各LED光源光谱分布的情况下,调光计算方法不用通过测量混合光源光谱分布,便能快速有效地计算出混合光源照度、相关色温、节律因子。

Antitumour effects on human colorectal carcinomas cells by stable silencing of phospholipase C-gamma 1 with lentivirus-delivered siRNA

Background In most colorectal carcinomas, the level of phospholipase C （PLC）-gamma 1 expression is greatly elevated. Increased expression of PLC-gamma 1 may play an important role in colon carcinogenesis, but the mechanism is not well known. The aim of this study was to evaluate the role of PLC-gamma 1 in colon carcinogenesis by using recombinant lentivirus that stably suppressed the PLC-gamma 1 expression in human colorectal carcinoma LoVo cells. Methods Recombinant lentivirus producing PLC-gamma 1 siRNA were prepared. After LoVo cells were transduced by each lentivirus, stably transduced cells were selected by Blasticidin. The protein and mRNA expression of PLC-gamma 1 were examined by Western-blot and reverse transcription-polymerase chain reaction （RT-PCR） analysis, and the effects of the lentivirus on the cell adhesion, migration and apoptosis were analyzed. Results Stable LoVo cell line deficient in PLC-gamma 1, was established. Notably, PLC-gamma 1 was silenced without affecting the levels of other subtypes of PLC so that the role of PLC-gamma 1 in colon carcinogenesis could be examined Silencing of endogenous PLC-gamma 1 resulted in efficient inhibition of the adhesion and migration of LoVo cells in vitro and a great increase of 5-fluorouracil induced apoptosis （30%-40%） of LoVo cells.Conclusions PLC-gamma 1 may play an important role in metastasis and anti-apoptosis in human colorectal carcinomas.