将连续变化的碰撞能量与串联质谱相结合,建立了能量分辨质谱(Energy-resolved mass spectrometry,ERMS)分析方法用以区分和检测人参皂苷同分异构体20(S)-Rf和Rg_(1).ERMS将子离子与母离子强度的比值定义为强度分数(Intensity fraction,I...将连续变化的碰撞能量与串联质谱相结合,建立了能量分辨质谱(Energy-resolved mass spectrometry,ERMS)分析方法用以区分和检测人参皂苷同分异构体20(S)-Rf和Rg_(1).ERMS将子离子与母离子强度的比值定义为强度分数(Intensity fraction,IF),两个子离子强度的比值定义为强度比(Intensity ratio,IR),并通过IF和IR分别对连续变化的碰撞能量作图建立特征碎片离子的IF和IR曲线.虽然20(S)-Rf和Rg_(1)的串联质谱图无明显差异,但是多元统计分析结果显示其特征碎片离子[M-Glc-H]-,[M-2Glc-H]-和[M-2Glc-C_(6)H_(12)-H]-的IF和IR曲线差异显著,有明显的区分边界,可以直接区分20(S)-Rf和Rg_(1).进一步利用ERMS实时分析了原人参三醇型皂苷生物转化产物中20(S)-Rf和Rg_(1)的相对摩尔含量.结果表明,ERMS不需液相色谱分离即可实现20(S)-Rf和Rg_(1)的快速区分和相对含量检测.展开更多
The discovery of a wild abortive-type(WA)cytoplasmic male sterile(CMS)line and breeding its restorer line have led to the commercialization of three-line hybrid rice,contributing considerably to global food security.H...The discovery of a wild abortive-type(WA)cytoplasmic male sterile(CMS)line and breeding its restorer line have led to the commercialization of three-line hybrid rice,contributing considerably to global food security.However,the molecular mechanisms underlyingfertility abortion and the restoration of CMs-WA lines remain largely elusive.In this study,we cloned a restorer gene,Rf2o,following a genome-wide association study analysis of the core parent lines of three-line hybrid rice.We found that Rf20 was present in all core parental lines,but different haplotypes and structural variants of its gene resulted in differences in Rf2o expression levels between sterileand restored lines.Rf20 could restorepollen fertility in the CMS-WA line and was found to be responsible for fertility restoration in some CMs lines under high temperatures.In addition,we found that Rf20 encodes a pentatricopeptide repeat protein that competes with WA352 for binding with COX11.This interaction enhances Cox11's function as a scavenger of reactive oxygen species,which in turn restores pollenfertility.Collectively,ourstudysuggestsanewactionmodeforpentatricopeptide repeatproteins inthe fertilityrestorationofCMs lines,providing an essential theoretical basisforbreedingrobustrestorer lines and for overcoming high temperature-induced fertility recovery of some CMS lines.展开更多
A novel large-signal equivalent circuit model of RF-SOI LDMOS based on Philips MOS Model 20 （MM20） is presented. The weak avalanche effect and the power dissipation caused by self-heating are described. The RF paras...A novel large-signal equivalent circuit model of RF-SOI LDMOS based on Philips MOS Model 20 （MM20） is presented. The weak avalanche effect and the power dissipation caused by self-heating are described. The RF parasitic elements are extracted directly from measured S-parameters with analytical methods. Their final values can be obtained quickly and accurately through the necessary optimization. The model is validated in DC,AC small-signal,and large-signal analyses for an RF-SOI LDMOS of 20-fingers （channel mask length, L = 1μm,finger width, W = 50μm） gate with high resistivity substrate and body-contact. Excellent agreement is achieved between simulated and measured results for DC, S- parameters （10MHz-0.01GHz）, and power characteristics, which shows our model is accurate and reliable. MM20 is improved for RF-SOI LDMOS large-signal applications. This model has been implemented in Verilog-A using the ADS circuit simulator （hpeesofsim）.展开更多
文摘将连续变化的碰撞能量与串联质谱相结合,建立了能量分辨质谱(Energy-resolved mass spectrometry,ERMS)分析方法用以区分和检测人参皂苷同分异构体20(S)-Rf和Rg_(1).ERMS将子离子与母离子强度的比值定义为强度分数(Intensity fraction,IF),两个子离子强度的比值定义为强度比(Intensity ratio,IR),并通过IF和IR分别对连续变化的碰撞能量作图建立特征碎片离子的IF和IR曲线.虽然20(S)-Rf和Rg_(1)的串联质谱图无明显差异,但是多元统计分析结果显示其特征碎片离子[M-Glc-H]-,[M-2Glc-H]-和[M-2Glc-C_(6)H_(12)-H]-的IF和IR曲线差异显著,有明显的区分边界,可以直接区分20(S)-Rf和Rg_(1).进一步利用ERMS实时分析了原人参三醇型皂苷生物转化产物中20(S)-Rf和Rg_(1)的相对摩尔含量.结果表明,ERMS不需液相色谱分离即可实现20(S)-Rf和Rg_(1)的快速区分和相对含量检测.
基金Biological Breeding-Major Projects(2023ZD04076)National Key Research and Development Project(2022YFD1200800)+1 种基金Hunan Natural Science Foundation(2023JJ30442)Special Funds for the Construction of Innovative Provinces in Hunan Province(2021NK1002).
文摘The discovery of a wild abortive-type(WA)cytoplasmic male sterile(CMS)line and breeding its restorer line have led to the commercialization of three-line hybrid rice,contributing considerably to global food security.However,the molecular mechanisms underlyingfertility abortion and the restoration of CMs-WA lines remain largely elusive.In this study,we cloned a restorer gene,Rf2o,following a genome-wide association study analysis of the core parent lines of three-line hybrid rice.We found that Rf20 was present in all core parental lines,but different haplotypes and structural variants of its gene resulted in differences in Rf2o expression levels between sterileand restored lines.Rf20 could restorepollen fertility in the CMS-WA line and was found to be responsible for fertility restoration in some CMs lines under high temperatures.In addition,we found that Rf20 encodes a pentatricopeptide repeat protein that competes with WA352 for binding with COX11.This interaction enhances Cox11's function as a scavenger of reactive oxygen species,which in turn restores pollenfertility.Collectively,ourstudysuggestsanewactionmodeforpentatricopeptide repeatproteins inthe fertilityrestorationofCMs lines,providing an essential theoretical basisforbreedingrobustrestorer lines and for overcoming high temperature-induced fertility recovery of some CMS lines.
文摘A novel large-signal equivalent circuit model of RF-SOI LDMOS based on Philips MOS Model 20 （MM20） is presented. The weak avalanche effect and the power dissipation caused by self-heating are described. The RF parasitic elements are extracted directly from measured S-parameters with analytical methods. Their final values can be obtained quickly and accurately through the necessary optimization. The model is validated in DC,AC small-signal,and large-signal analyses for an RF-SOI LDMOS of 20-fingers （channel mask length, L = 1μm,finger width, W = 50μm） gate with high resistivity substrate and body-contact. Excellent agreement is achieved between simulated and measured results for DC, S- parameters （10MHz-0.01GHz）, and power characteristics, which shows our model is accurate and reliable. MM20 is improved for RF-SOI LDMOS large-signal applications. This model has been implemented in Verilog-A using the ADS circuit simulator （hpeesofsim）.
