收发组合作为无人机数据链系统的核心部件,其抗电磁干扰能力直接影响机载通信安全。为检验核电磁脉冲(HEMP)辐照条件下某型无人机数据链系统的可靠性,基于快沿电磁脉冲模拟系统建立了无人机HEMP效应试验平台,以典型"失锁"效...收发组合作为无人机数据链系统的核心部件,其抗电磁干扰能力直接影响机载通信安全。为检验核电磁脉冲(HEMP)辐照条件下某型无人机数据链系统的可靠性,基于快沿电磁脉冲模拟系统建立了无人机HEMP效应试验平台,以典型"失锁"效应作为受干扰判别依据,开展了无人机数据链系统辐照效应研究,分析了无人机数据链"失锁"效应机理。结果表明:核电磁脉冲场强达到72 k V/m时能够对飞机数据链测试系统产生干扰,导致地面监视系统回报通信链路全部失锁、飞行控制模拟器黑屏,且收发组合放置姿态改变基本不影响数据链系统干扰阈值。通过电磁仿真分析发现,飞行控制模拟器端接电缆耦合外界强场信号使收发组合供电瞬时中断,进而导致数据链测试系统产生干扰。排除数据链测试系统中飞行控制模拟器,在辐照场强<90 k V/m情况下,无人机下行遥测链路不会出现失锁。展开更多
AIM： To observe the inhibition of hepatitis B virus （HBV） replication and expression in HepG2.2.15 cells by combination of small interfering RNAs （siRNAs）. METHODS： Recombinant plasmid psiI-HBV was constructed a...AIM： To observe the inhibition of hepatitis B virus （HBV） replication and expression in HepG2.2.15 cells by combination of small interfering RNAs （siRNAs）. METHODS： Recombinant plasmid psiI-HBV was constructed and transfected into HepG2.2.15 cells. At 48 h, 72 h and 96 h after transfection, culture media were collected and cells were harvested for HBV replication assay. HBsAg and HBeAg in the cell culture medium were detected by enzyme-linked immunoadsorbent assay （ELISA）. Intracellular viral DNA and covalently closed circular DNA （cccDNA） were quantified by real-time polymerase chain reaction （PCR）. HBV viral mRNA was reverse transcribed and quantified by reverse-transcript PCR （RT-PCR）. RESULTS： siRNAs showed marked anti-HBV effects. siRNAs could specifically inhibit the expression of HBsAg and the replication of HBV DNA in a dosedependent manner. Furthermore, combination of siRNAs, compared with individual use of each siRNA, exerted a stronger inhibition on antigen expression and viral replication. More importantlycombination of siRNAs significantly suppressed HBV cccDNA amplification. CONCLUSION： Combination of siRNAs mediates a stronger inhibition on viral replication and antigenexpression in HepG2.2.15 cells, especially on cccDNA amplification.展开更多
Purpose: The transforming growth factor beta1 (TGFB1) pathway has been linked to fibrosis in several tissues including skin, liver, kidney and the cornea. In this study, a RNA interference-based approach using siRNAs ...Purpose: The transforming growth factor beta1 (TGFB1) pathway has been linked to fibrosis in several tissues including skin, liver, kidney and the cornea. In this study, a RNA interference-based approach using siRNAs targeting three critical scarring genes, TGFB1, TGFB receptor 2 (TGFBR2) and connective tissue growth factor (CTGF), was tested for effects on reducing alpha smooth muscle actin (SMA) and corneal scarring (haze) in excimer laser ablated rabbit corneas. Methods: Levels of TGFB1 and CTGF mRNAs were measured using qRT-PCR in the epithelial and endothelial cell layers of normal and excimer ablated rabbit corneas at 30 minutes, 1 day and 2 days after ablation. Two different scarring models were utilized to assess the effects of the triple siRNA combination on corneal scarring. In the first model, rabbit corneas were unevenly ablated creating a mesh pattern then treated immediately with the triple siRNA combination. After 1 day the ablated areas of corneas were collected and levels of mRNAs for TGFB1, TGFBR2 and CTGF were measured. After 14 days, levels of mRNA for SMA were measured and SMA protein immunolocalized in frozen sections. In the second model, rabbit corneas were uniformly ablated to a depth of 155 microns followed by three daily doses of the triple combination of siRNA. After 14 days, corneas were photographed and images were analyzed using Image J software to assess corneal scarring. Corneas were also analyzed for levels of SMA mRNA. Results: In both unwounded and wounded corneas, levels of TGFB1 and CTGF mRNA were always significantly higher in endothelial cells than in epithelial cells (10 to 30 fold). Thirty minutes after injury, levels of both TGFB1 and CTGF mRNAs increased approximately 20-fold in both epithelial and endothelial cells, and further increased approximately 60-fold in 2 days. In the first therapeutic experiment with a single siRNA dose, two of three rabbits showed substantial reductions of all three target genes after 1 day with a maximum knock down of 80% of TGFb 1, 50% red展开更多
文摘收发组合作为无人机数据链系统的核心部件,其抗电磁干扰能力直接影响机载通信安全。为检验核电磁脉冲(HEMP)辐照条件下某型无人机数据链系统的可靠性,基于快沿电磁脉冲模拟系统建立了无人机HEMP效应试验平台,以典型"失锁"效应作为受干扰判别依据,开展了无人机数据链系统辐照效应研究,分析了无人机数据链"失锁"效应机理。结果表明:核电磁脉冲场强达到72 k V/m时能够对飞机数据链测试系统产生干扰,导致地面监视系统回报通信链路全部失锁、飞行控制模拟器黑屏,且收发组合放置姿态改变基本不影响数据链系统干扰阈值。通过电磁仿真分析发现,飞行控制模拟器端接电缆耦合外界强场信号使收发组合供电瞬时中断,进而导致数据链测试系统产生干扰。排除数据链测试系统中飞行控制模拟器,在辐照场强<90 k V/m情况下,无人机下行遥测链路不会出现失锁。
基金The Youth Foundation of Heilongjiang Province,No.QC06C061the Foundation of Education Department,Heilongjiang Province,No.11521089
文摘AIM： To observe the inhibition of hepatitis B virus （HBV） replication and expression in HepG2.2.15 cells by combination of small interfering RNAs （siRNAs）. METHODS： Recombinant plasmid psiI-HBV was constructed and transfected into HepG2.2.15 cells. At 48 h, 72 h and 96 h after transfection, culture media were collected and cells were harvested for HBV replication assay. HBsAg and HBeAg in the cell culture medium were detected by enzyme-linked immunoadsorbent assay （ELISA）. Intracellular viral DNA and covalently closed circular DNA （cccDNA） were quantified by real-time polymerase chain reaction （PCR）. HBV viral mRNA was reverse transcribed and quantified by reverse-transcript PCR （RT-PCR）. RESULTS： siRNAs showed marked anti-HBV effects. siRNAs could specifically inhibit the expression of HBsAg and the replication of HBV DNA in a dosedependent manner. Furthermore, combination of siRNAs, compared with individual use of each siRNA, exerted a stronger inhibition on antigen expression and viral replication. More importantlycombination of siRNAs significantly suppressed HBV cccDNA amplification. CONCLUSION： Combination of siRNAs mediates a stronger inhibition on viral replication and antigenexpression in HepG2.2.15 cells, especially on cccDNA amplification.
文摘Purpose: The transforming growth factor beta1 (TGFB1) pathway has been linked to fibrosis in several tissues including skin, liver, kidney and the cornea. In this study, a RNA interference-based approach using siRNAs targeting three critical scarring genes, TGFB1, TGFB receptor 2 (TGFBR2) and connective tissue growth factor (CTGF), was tested for effects on reducing alpha smooth muscle actin (SMA) and corneal scarring (haze) in excimer laser ablated rabbit corneas. Methods: Levels of TGFB1 and CTGF mRNAs were measured using qRT-PCR in the epithelial and endothelial cell layers of normal and excimer ablated rabbit corneas at 30 minutes, 1 day and 2 days after ablation. Two different scarring models were utilized to assess the effects of the triple siRNA combination on corneal scarring. In the first model, rabbit corneas were unevenly ablated creating a mesh pattern then treated immediately with the triple siRNA combination. After 1 day the ablated areas of corneas were collected and levels of mRNAs for TGFB1, TGFBR2 and CTGF were measured. After 14 days, levels of mRNA for SMA were measured and SMA protein immunolocalized in frozen sections. In the second model, rabbit corneas were uniformly ablated to a depth of 155 microns followed by three daily doses of the triple combination of siRNA. After 14 days, corneas were photographed and images were analyzed using Image J software to assess corneal scarring. Corneas were also analyzed for levels of SMA mRNA. Results: In both unwounded and wounded corneas, levels of TGFB1 and CTGF mRNA were always significantly higher in endothelial cells than in epithelial cells (10 to 30 fold). Thirty minutes after injury, levels of both TGFB1 and CTGF mRNAs increased approximately 20-fold in both epithelial and endothelial cells, and further increased approximately 60-fold in 2 days. In the first therapeutic experiment with a single siRNA dose, two of three rabbits showed substantial reductions of all three target genes after 1 day with a maximum knock down of 80% of TGFb 1, 50% red
