Radio-resistance induced by nitric oxide to heavy ion irradiation in A172 human glioma cells

To investigate effects of nitric oxide on cellular radio-sensitivity, three human glioma cell lines, i.e. A172, A172 transfected green fluorescence protein (EGFP) gene (EA172) and A172 transfected inducible nitric oxide synthesis (iNOS) gene (iA172), were irradiated by 12C6 ions to 0, 1 or 2Gy. Productions of nitric oxide and glutathione (GSH) in A172, EA172 and iA172 were determined by chemical methods, cell cycle was analyzed by flow cytometry at the 24th hour after irradiation, and survival fraction of the cells was measured by colorimetric MTT assay at the 5th day after irradiation. The results showed that the concentrations of nitric oxide and GSH in iA172 were significantly higher than in A172 and EA172; the G2/M stage arrest induced by the 12C6 ion irradiation was observed in A172 and EA172 but not in iA172 at the 24th hour after exposure; and the survival fraction of iA172 was higher than that of EA172 and iA172. Data suggest that the radio-sensitivity of the A172 was reduced after the iNOS gene transfection. The increase of GSH production and the change of cellular signals such as the cell cycle control induced by nitric oxide may be involved in this radio-resistance.     

Effect of doping of different rare earth (europium,gadolinium, dysprosium and neodymium) metal ions on structural,optical and photocatalytic properties of LaFeO3 perovskites

Different rare earth substituted perovskites LaRE_xFe_(1-x)O_3(where RE=Eu~(3+),Gd~(3+),Dy~(3+),Nd~(3+)and x=0.02,0.04,0.06,0.08,0.1) with orthorhombic structure and narrow band gaps were successfully fabricated via sol-gel autocombustion method.All the substituted perovskites are found to exhibit excellent photocatalytic activity towards the oxidative degradation of dye molecules.An excellent increase in the rate constant values of pure perovskite(LaFeO_3) photocatalytic reactions is observed with the substitution of rare earth metal ions.Best results are obtained for LaNd_(0.1)Fe_(0.9)O_3 which exhibits around 7 times increase in the rate constant values for degradation reaction of SO(1.76×10~(-1) min~(-1))and RBY(1.69×10~(-1) min~(-1)) dyes.     

偶联剂改性对脱水坡缕石摩擦材料摩擦磨损性能影响

通过实验.得到铝锆偶朕剂和XD-172硅烷类偶联剂最佳改性工艺,研究了不同偶联剂对脱水坡缕石摩擦材料摩擦磨损性能的影响.结果表明,在低温段性能影响较小,但在超过200℃的高温阶段,脱水坡缕石摩擦材料的摩擦系数可提高50%以上,磨损率可降低约70%,两种偶联荆改性效果都显著,但总体上铝锆偶联荆改性效果明显优于XD-172.     

大斜度长裸眼定向井钻井完井技术

介绍了临盘油田商25-斜172大斜度长裸眼双靶点定向井各井段施工技术，胺盐聚合物钻井完井液的技术要点及固井作业技术措施，探讨了大斜度长裸眼定向井井身轨迹控制，钻具组合优选，压差卡钻处理，岩屑携带及固井作业等问题，并有针对性地提出了相应技术措施。     

单侧调整纠偏机构在悬臂结构接口部件中的应用

YF172滤棒固化储存输送装置采用的可调式悬臂结构接口部件在实际应用过程中,有几台设备在对接后有输送带跑偏、乱棒等现象,影响了滤棒输送质量。经过改进设计的单侧调整纠偏机构的从动带轮组件,只需打开对接机的玻璃门,就可以直观、快速地调整从动轮轴线与输送带中心垂直,较好地解决输送带跑偏的问题,提高了滤棒的输送质量,增强了设备的稳定性。     

Over-Expression of GmGIa-Regulated Soybean miR172a Confers Early Flowering in Transgenic Arabidopsis thaliana

Flowering is a pivotal event in the life cycle of plants. miR172 has been widely confirmed to play critical roles in flowering time control by regulating its target gene expression in Arabidopsis. However, the role of its counterpart in soybean remains largely unclear. In the present study, we found that the gma-miR172a was regulated by a GIGANTEA ortholog, GmGIa, in soybean through miRNA metabolism. The expression analysis revealed that gma-miR172a has a pattern of diurnal rhythm expression and its abundance increased rapidly as plants grew until the initiation of flowering phase in soybean. One target gene of gma-miR172a, Glyma03g33470, was predicted and verified using a modified RLM 5′-RACE (RNA ligase-mediated rapid amplification of 5′ cDNA ends) assay. Overexpression of gma-miR172a exhibited an early flowering phenotype and the expression of FT, AP1 and LFY were simultaneously increased in gma-miR172a-transgenic Arabidopsis plants, suggesting that the early flowering phenotype was associated with up-regulation of these genes. The overexpression of the gma-miR172a-resistant version of Glyma03g33470 weakened early flowering phenotype in the toe1 mutant of Arabidopsis. Taken together, our results suggested that gma-miR172a played an important role in GmGIa-mediated flowering by repressing Glyma03g33470, which in turn increased the expression of FT, AP1 and LFY to promote flowering in soybean.     

6SE70变频器加脉冲编码器实现位置控制

简述了管坯提升设备位置控制的几种方式,重点叙述了使用脉冲编码器(带零通道)和西门子6SE70变频器经过程序运算实现精确位置控制的方法。     

港西油田港172断块气顶边水油藏高效开发技术研究

港172断块是一个气顶边水构造油气藏,通过对其气顶和边水能量的研究分析,确定了该断块的开发程序。首先充分利用气顶和边水能量,开发动用纯油区;此后边外注水补充地层能量开发动用缓冲区;最后在开发过程中深化认识油藏,合理调整开发方案。投入开发以来,该油藏获得了连续7年的高速高效开发。从采油速度、稳产年限、采收率等油藏开发主要指标分析,港172断块属于一类开发水平,预计最终油藏水驱采收率可达40.8%。开发实践表明,这套开发方式不仅使该类油藏有较高的开采速度,而且确保达到了良好的开发效果。