Fine Particulate Matter Exposure Induces Toxicity by Regulating Nuclear Factor-κB/toll-like Receptor 4/myeloid Differentiation Primary Response Signaling Pathways in RAW264.7 Cells

Global air pollution has become a major threat to human health. Daily variations in air pollution have been linked to increased risks of cardiopulmonaryrelated morbidity and mortality. In particular, fine particulate matter(PM) with an aerodynamic diameter ≤ 2.5 μm(PM2.5), which mostly originates from coal combustion, vehicle exhaust, and open sources in Chinese cities, is detrimental to health[1].Epidemiological and experimental investigations have demonstrated that long-term exposure to PM2.5, the most dangerous particulate in the Earth’s atmosphere, is a pivotal risk factor for cardiorespiratory diseases.

高效液相色谱法测定婴儿配方奶粉中乳糖和蔗糖含量的前处理方法优化

目的优化GB 5413.5-2010《食品安全国家标准婴幼儿食品和乳品中乳糖、蔗糖的测定》(第一法)中前处理步骤。方法样品先用15 mL热水溶解,再加入乙酸锌、亚铁氰化钾溶液各2 mL,涡旋振荡超声,加水定容到50 mL,离心过滤,最终通过高效液相色谱仪测定。结果测定乳糖含量较低的样品时,国标测定的结果与本方法相近,2种方法的相对标准偏差为0.22%。国标方法的样品加标回收率为99.0%,本方法为99.7%。本方法样品重复6次,蔗糖重复性的相对标准偏差为0.593%,乳糖为1.24%。当国标方法测定乳糖含量较高的样品时,会出现糖析出的问题,测得乳糖的含量远低于本方法。结论本方法解决了国标前处理出现的样品糖析出问题。研究结果表明本方法的精密度高、准确度高,线性范围良好,操作简单,是测定婴儿配方奶粉中蔗糖和乳糖含量的有效方法。