By using a ray method, a physical model that the backscattering of a tube is simplilied into reflection of a plane wave on layered media is suggested and reconstruction formulas of the parameters of a metallic tube co...By using a ray method, a physical model that the backscattering of a tube is simplilied into reflection of a plane wave on layered media is suggested and reconstruction formulas of the parameters of a metallic tube covered with sound-absorbing materials under the conditions of high frequency, fard field and thin tube are given. The internal and external radii of an aluminium tube filled by water or air and thickness of the covered material are reconstructed by using computer simulation and experimellts. The theoretical tesults obtained by this method are supported by experiments.展开更多
目的分析枸杞多糖对过氧化氢所致人肾小管上皮细胞(human kidney,HK-2)的损伤情况、细胞内自噬蛋白表达以及细胞外调节蛋白激酶(extracellular regulated protein kinases,ERK)/哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,m...目的分析枸杞多糖对过氧化氢所致人肾小管上皮细胞(human kidney,HK-2)的损伤情况、细胞内自噬蛋白表达以及细胞外调节蛋白激酶(extracellular regulated protein kinases,ERK)/哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)通路的激活情况,探讨枸杞多糖改善其氧化损伤的作用机制。方法体外培养人源性HK-2细胞,根据处理方式不同分为对照组、枸杞多糖组、氧化应激组及干预组。对照组使用细胞培养液;枸杞多糖组使用含有枸杞多糖的细胞培养液;氧化应激组使用含有过氧化氢的细胞培养液;干预组先用枸杞多糖细胞培养液孵育24 h,再滴加过氧化氢孵育30 min,每组处理时间相同。观察每组细胞的生长状态;使用细胞活力检测盒分析各组细胞的存活率;比色法分析胞质所含丙二醛(malondialdehyde,MDA)的量及超氧化物歧化酶(superoxide dismutase,SOD)的活性;蛋白印迹评估胞质内自噬蛋白微管相关蛋白轻链3(microtubule-associated protein light chain 3,LC3)及ERK/mTOR通路相关蛋白ERK、磷酸化-ERK(phosphorylation ERK,p-ERK)、mTOR和磷酸化-mTOR(phosphorylation mTOR,p-mTOR)的含量。结果与对照组比较,枸杞多糖组细胞生长状态、存活率、胞质所含MDA含量和SOD活性、自噬蛋白LC3及ERK/mTOR通路相关蛋白ERK、p-ERK、mTOR和p-mTOR的含量比较,差异均无统计学意义(均P>0.05);氧化应激组细胞皱缩、悬浮较多,存活率[(51.16±4.85)%]下降、MDA[(4.78±0.81)mmol/L]升高、SOD[(10.11±1.17)U/L]降低,胞质内LC3Ⅱ/LC3Ⅰ[(0.391±0.058)]降低、p-ERK/ERK[(1.526±0.185)]、p-mTOR/mTOR[(1.423±0.174)]升高(均P<0.05)。干预组与氧化应激组相比,细胞状态好转,悬浮少,存活率[(86.29±4.55)%]上升、MDA[(2.22±0.46)mmol/L]下降、SOD[(18.25±2.33)U/L]升高,胞质内LC3Ⅱ/LC3Ⅰ[(0.846±0.091)]升高、p-ERK/ERK[(0.906±0.127)]、p-mTOR/m[TOR(0.820±0.092)]降低(均P<0.05)。结论枸杞多糖能抑制过氧化氢刺激的HK-2内的ERK/mTOR信号通路,增强细胞的自噬作用,提高细胞存活率,改善其氧化损伤。展开更多
文摘By using a ray method, a physical model that the backscattering of a tube is simplilied into reflection of a plane wave on layered media is suggested and reconstruction formulas of the parameters of a metallic tube covered with sound-absorbing materials under the conditions of high frequency, fard field and thin tube are given. The internal and external radii of an aluminium tube filled by water or air and thickness of the covered material are reconstructed by using computer simulation and experimellts. The theoretical tesults obtained by this method are supported by experiments.
