AIM To investigate the pathogenic effect ofSEB and D-GalN on liver and the protection ofcyclosporin A, the relationship between hepaticapoptosis and necrosis and the possiblemechanism of acute hepatic necrosis.METHODS...AIM To investigate the pathogenic effect ofSEB and D-GalN on liver and the protection ofcyclosporin A, the relationship between hepaticapoptosis and necrosis and the possiblemechanism of acute hepatic necrosis.METHODS After staphylococcal enterotoxin B(SEB ) mixed with D--galactosamine (D-GaiN )were injected intraperitoneally into Balb/c miceand those previously treated with cyclosporin A,blood samples were collected and livers wereisolated at 2, 6, 12 and 24 h. Patterns othepatocellular death were studiedmorphologically and biochemically, circulatingcytokines (TNF-a, IFN--y ) and mice mortalitywithin 24h was assessed.RESU’LTS The SEB could induce the typicalapoptotic changes of hepatocytes, the D-GaiNcould induce hepatocytes apoptosis anddegeneration at the same time, and the micehaving received the SEB + D-GaiN injectionsdeveloped apoptosis at 2 and 6 h, but after 12 hhepatocytes were characterized by severein jury, whereas all the examinations in thecyclosporin A treated mice were normal.CONCLUSION Hepatic cell apoptosis might berelated to necrosis, and massive hepatocyteapoptosis is likely the initiating step of acutehepatic necrosis in mice. The effects induced bySEB and D--GaiN on hepatocytes might bemediated by T cells, and could be prevented bycyclosporin A.展开更多
在卫星信号接收的过程中,量化是模数转换的重要环节,信号量化会带来能量损失,对于信号后续的处理产生影响,根据信号特性选取合适的量化位数和系统基准功率可以有效改善这种损失.本文采用量化前后信号信噪比(signal to noise ratio,SNR)...在卫星信号接收的过程中,量化是模数转换的重要环节,信号量化会带来能量损失,对于信号后续的处理产生影响,根据信号特性选取合适的量化位数和系统基准功率可以有效改善这种损失.本文采用量化前后信号信噪比(signal to noise ratio,SNR)对比的形式来直观表示量化损耗,并给出了一般性分析公式.说明了自动增益控制(automatic gain control,AGC)模块在信号量化中的作用,结合量化损耗公式,通过确定最佳增益系数给出了一种基准功率的选取方式,使得不同SNR的信号量化损耗明显降低.仿真结果表明:在低位量化时,该方式对卫星导航信号的量化损耗能改善约1.5 dB.该分析对于接收机的设计以及工程实现具有一定的参考意义.展开更多
The objective of this study was to study the distribution characteristics of Mongolian drug Digeda-4 decoction in rats with acute liver injury.The Mongolian drug Digeda-4decoction was administered intragastric in rats...The objective of this study was to study the distribution characteristics of Mongolian drug Digeda-4 decoction in rats with acute liver injury.The Mongolian drug Digeda-4decoction was administered intragastric in rats with acute liver injury induced by D-GalN.The removal of the Liver,spleen,lung,kidney and heart,10%tissue homogenate展开更多
基于双铁心磁通门负反馈工作原理,设计了一种数字磁通门磁强计。利用可编程运算放大器实时调节磁通门输出信号的幅值,再经高速12 bit A/D转换成数字信号,用ARM微控制器完成相敏整流和积分运算,用高精度16 bit D/A输出反馈信号,构成闭环...基于双铁心磁通门负反馈工作原理,设计了一种数字磁通门磁强计。利用可编程运算放大器实时调节磁通门输出信号的幅值,再经高速12 bit A/D转换成数字信号,用ARM微控制器完成相敏整流和积分运算,用高精度16 bit D/A输出反馈信号,构成闭环系统。实验测试表明,该磁强计的量程为±62 000 nT,分辨率为1.9 nT,线性度达到了2.4×10-4。采用可编程运放结合12 bit A/D实现16 bit分辨率的设计方案,降低了磁强计成本,具有工程应用前景。展开更多
文摘AIM To investigate the pathogenic effect ofSEB and D-GalN on liver and the protection ofcyclosporin A, the relationship between hepaticapoptosis and necrosis and the possiblemechanism of acute hepatic necrosis.METHODS After staphylococcal enterotoxin B(SEB ) mixed with D--galactosamine (D-GaiN )were injected intraperitoneally into Balb/c miceand those previously treated with cyclosporin A,blood samples were collected and livers wereisolated at 2, 6, 12 and 24 h. Patterns othepatocellular death were studiedmorphologically and biochemically, circulatingcytokines (TNF-a, IFN--y ) and mice mortalitywithin 24h was assessed.RESU’LTS The SEB could induce the typicalapoptotic changes of hepatocytes, the D-GaiNcould induce hepatocytes apoptosis anddegeneration at the same time, and the micehaving received the SEB + D-GaiN injectionsdeveloped apoptosis at 2 and 6 h, but after 12 hhepatocytes were characterized by severein jury, whereas all the examinations in thecyclosporin A treated mice were normal.CONCLUSION Hepatic cell apoptosis might berelated to necrosis, and massive hepatocyteapoptosis is likely the initiating step of acutehepatic necrosis in mice. The effects induced bySEB and D--GaiN on hepatocytes might bemediated by T cells, and could be prevented bycyclosporin A.
文摘在卫星信号接收的过程中,量化是模数转换的重要环节,信号量化会带来能量损失,对于信号后续的处理产生影响,根据信号特性选取合适的量化位数和系统基准功率可以有效改善这种损失.本文采用量化前后信号信噪比(signal to noise ratio,SNR)对比的形式来直观表示量化损耗,并给出了一般性分析公式.说明了自动增益控制(automatic gain control,AGC)模块在信号量化中的作用,结合量化损耗公式,通过确定最佳增益系数给出了一种基准功率的选取方式,使得不同SNR的信号量化损耗明显降低.仿真结果表明:在低位量化时,该方式对卫星导航信号的量化损耗能改善约1.5 dB.该分析对于接收机的设计以及工程实现具有一定的参考意义.
文摘The objective of this study was to study the distribution characteristics of Mongolian drug Digeda-4 decoction in rats with acute liver injury.The Mongolian drug Digeda-4decoction was administered intragastric in rats with acute liver injury induced by D-GalN.The removal of the Liver,spleen,lung,kidney and heart,10%tissue homogenate
文摘基于双铁心磁通门负反馈工作原理,设计了一种数字磁通门磁强计。利用可编程运算放大器实时调节磁通门输出信号的幅值,再经高速12 bit A/D转换成数字信号,用ARM微控制器完成相敏整流和积分运算,用高精度16 bit D/A输出反馈信号,构成闭环系统。实验测试表明,该磁强计的量程为±62 000 nT,分辨率为1.9 nT,线性度达到了2.4×10-4。采用可编程运放结合12 bit A/D实现16 bit分辨率的设计方案,降低了磁强计成本,具有工程应用前景。
