气质联用测定橡胶中的的11种N-亚硝胺物质的释放量

根据GB28482-2002对橡胶制品的亚硝胺和亚硝胺盐的释放量进行测试,为了快速,高效的检测橡胶制品中的N-亚硝胺物质的释放量,对样品前处理和GCMS的条件进行优化,建立了气相色谱-质谱联用测定橡胶制品的N-亚硝胺物质的释放量,方法线性范围0.05~2.00 mg/L,线性相关系数大于0.999,检出限达到0.05 mg/L,重复性实验得到相对标准偏差小于5%,加标回收率为85%~115%.满足GB28482-2002对橡胶制品的N-亚硝胺物质的释放量测试要求，

二甲基亚硝胺诱导大鼠肝纤维化模型的探讨

建立二甲基亚硝胺制作化学性肝纤维动物模型,并对模型进行评价与探讨。方法:采用不同浓度的二甲基亚硝胺间断腹腔注射大鼠诱导肝纤维化模型。利用放射免疫法分析肝纤维化四项、肝纤维化半定量分析评价大鼠肝纤维化程度。结果:低浓度组、高浓度组血清肝纤维化指标(HA、LN、PCIII、IV-C)均明显高于实验对照组(p<0.01)。低浓度组、高浓度组半定量分析均明显高于实验对照组(p<0.01)。结论:间断腹腔注射DMN是一种稳定可靠的化学性肝纤维化研究模型。

Completely Autotrophic Nitrogen-removal over Nitrite in Two Types of Reactors

Two lab-scale reactors, suspended-sludge and fluidized.bed, were conducted with the feed of ammonium-rich synthetic wastewater devoid of COD. Completely autotrophic nitrogen-removal process was fulfilled in both reactors and the maximum efficiencies of nitrogen removal were achieved, 65% in the suspended-sludge reactor and 73% in the fluidized-bed reactor respectively. Different from the steady performance of the fluldized-bed reactor, the suspended-sludge reactor came to deteriorate constantly after a period of stable operation, resulting in almost complete loss of the N-removal ability in the suspending system. Molecular methods such as PCR and FISH were employed for describing the microbial characteristics in two systems. This study suggests that a biofllm system is a suitable configuration for completely autotrophic N-removal with more feasibility and stability than a suspending system.

室内存放农药化肥有损人体健康

不少农户经常将买回或使用后剩余的农药化肥存放在自己的卧室里、屋角、窗下、柜顶、床底等处。造成了人药混居的现象，这种做法是非常不卫生、不利于人体健康的，应引起人们的注意。