Heterodimerization in RTKs is of vital importance in the RTK signaling and cell functions.Heterodimerization between RTKs can result in diversity of downstream signals,increasing the ability of cells to respond to ext...Heterodimerization in RTKs is of vital importance in the RTK signaling and cell functions.Heterodimerization between RTKs can result in diversity of downstream signals,increasing the ability of cells to respond to external experiments.Traditional RTKs heterodimerization always occur in the same families and is lack of agonists to activate the heterodimeric RTKs signaling pathway.Herein,we developed the DNA agonist based on bivalent aptamers for the heterodimerized RTKs of different families,AF/AM-1,which could simultaneously activate FGFR1 and c-Met signaling.It is the first agonist that realizing the heterodimerization and activation of FGFR1 and c-Met,two different RTK families.The activation of FGFR1/c-Met heterodimer result in the down-stream signals transduction,such as the phosphorylation of Akt and Erk,inducing the cell migration and proliferation.The DNA agonist for RTK heterodimer of different families would have potential applications in the fields of biomedicine.展开更多
实时动态差分(real time kinematic,RTK)定位技术因其成本低、实时性强等优点,已成为实时位移监测领域的重要技术手段.然而,随着跨海大桥、海上平台等远距离基础设施对高精度实时位移监测需求不断增长,常规RTK技术在长距离作业中,因测...实时动态差分(real time kinematic,RTK)定位技术因其成本低、实时性强等优点,已成为实时位移监测领域的重要技术手段.然而,随着跨海大桥、海上平台等远距离基础设施对高精度实时位移监测需求不断增长,常规RTK技术在长距离作业中,因测站间距离增加导致大气误差(对流层和电离层延迟)的空间相关性降低,差分后残余大气误差难以充分消除,严重影响模糊度的收敛从而影响定位精度.针对这一问题,提出一种大气误差附加约束的长距离RTK定位方法:1)将经先验模型改正并进行差分后残余的对流层和电离层延迟参数化并纳入估计模型,针对残余误差分别建立先验约束:对流层残差基于台站间高差和测站距离构建先验方差,更全面地刻画长距离条件下对流层残差的不确定性;电离层残差结合纬度相关性构建先验方差,实现对定位参数解算过程的稳健约束;2)考虑大气误差的时变特性,采用随机游走过程对对流层和电离层参数进行动态估计,电离层活动变化大,随机游走噪声建模考虑基线长度和卫星高度角变化,使动态估计更符合实际情况.基于国际GNSS服务组织(International GNSS Service,IGS)测站和海上平台实测数据开展试验,结果表明:相较于常规RTK方法,所提方法在不同的观测环境下均有效缩短了收敛时间和模糊度首次固定时间,显著提升了模糊度固定率,同时在水平和垂向定位精度上取得明显改善.展开更多
基金the National Natural Science Foundation of China(Nos.22104158,82174104,U1903211)the Natural Science Foundation of Hunan Province(No.2021JJ40041)+1 种基金Guangdong Basic and Applied Basic Research Foundation(No.2023A1515011346)Shenzhen Science and Technology Program(No.SZBH202130)。
文摘Heterodimerization in RTKs is of vital importance in the RTK signaling and cell functions.Heterodimerization between RTKs can result in diversity of downstream signals,increasing the ability of cells to respond to external experiments.Traditional RTKs heterodimerization always occur in the same families and is lack of agonists to activate the heterodimeric RTKs signaling pathway.Herein,we developed the DNA agonist based on bivalent aptamers for the heterodimerized RTKs of different families,AF/AM-1,which could simultaneously activate FGFR1 and c-Met signaling.It is the first agonist that realizing the heterodimerization and activation of FGFR1 and c-Met,two different RTK families.The activation of FGFR1/c-Met heterodimer result in the down-stream signals transduction,such as the phosphorylation of Akt and Erk,inducing the cell migration and proliferation.The DNA agonist for RTK heterodimer of different families would have potential applications in the fields of biomedicine.
文摘实时动态差分(real time kinematic,RTK)定位技术因其成本低、实时性强等优点,已成为实时位移监测领域的重要技术手段.然而,随着跨海大桥、海上平台等远距离基础设施对高精度实时位移监测需求不断增长,常规RTK技术在长距离作业中,因测站间距离增加导致大气误差(对流层和电离层延迟)的空间相关性降低,差分后残余大气误差难以充分消除,严重影响模糊度的收敛从而影响定位精度.针对这一问题,提出一种大气误差附加约束的长距离RTK定位方法:1)将经先验模型改正并进行差分后残余的对流层和电离层延迟参数化并纳入估计模型,针对残余误差分别建立先验约束:对流层残差基于台站间高差和测站距离构建先验方差,更全面地刻画长距离条件下对流层残差的不确定性;电离层残差结合纬度相关性构建先验方差,实现对定位参数解算过程的稳健约束;2)考虑大气误差的时变特性,采用随机游走过程对对流层和电离层参数进行动态估计,电离层活动变化大,随机游走噪声建模考虑基线长度和卫星高度角变化,使动态估计更符合实际情况.基于国际GNSS服务组织(International GNSS Service,IGS)测站和海上平台实测数据开展试验,结果表明:相较于常规RTK方法,所提方法在不同的观测环境下均有效缩短了收敛时间和模糊度首次固定时间,显著提升了模糊度固定率,同时在水平和垂向定位精度上取得明显改善.
