To measure the signals with high freq u ency(>500 MHz),a sampling frequency down conversion method is introduced.This pa per analyzes the intermodulation signals and figures out the relationship betwee n the interm...To measure the signals with high freq u ency(>500 MHz),a sampling frequency down conversion method is introduced.This pa per analyzes the intermodulation signals and figures out the relationship betwee n the intermodulation signal and intermediate frequenc y signal.Based on the frequency conversion technology,an exclusion algorithm i s proposed a nd the actual implementation of the algorithm is given.The application resu lts show that the exclusion algorithm can identify the intermodulation signal exactly and eliminate the bad influence on the frequency measurement.展开更多
As a pivotal signal pathway,the Ras/Raf/MEK/ERK cascade can be activated by multiple extracellular stimuli and can transmit signals to diverse substrates.It remains to be elucidated how so many different signals can b...As a pivotal signal pathway,the Ras/Raf/MEK/ERK cascade can be activated by multiple extracellular stimuli and can transmit signals to diverse substrates.It remains to be elucidated how so many different signals can be variously transferred by only two MEK molecules(MEK1 and MEK2) .Because of technological limitations the complete structures of the MEKs are still unavailable.Here,we report the full-length structure of MEK2 obtained by homology modeling and molecular dynamics simulations.The simulations show that the N-terminal part of MEK2 is highly flexible and this flexibility may enable MEK2 to interact with ERKs and other ligands in diverse manners that correspond to various upstream signals and downstream consequences.展开更多
文摘To measure the signals with high freq u ency(>500 MHz),a sampling frequency down conversion method is introduced.This pa per analyzes the intermodulation signals and figures out the relationship betwee n the intermodulation signal and intermediate frequenc y signal.Based on the frequency conversion technology,an exclusion algorithm i s proposed a nd the actual implementation of the algorithm is given.The application resu lts show that the exclusion algorithm can identify the intermodulation signal exactly and eliminate the bad influence on the frequency measurement.
基金supported by the National Natural Science Foundation of China(Grant No.30670791)the National Basic Research Program of China(Grant No.2009CB918301)+1 种基金the National High Technology Research and Development Program of China(Grant No.2008AA02Z124)the State Key Laboratory of Proteomics(Grant No.SKLP-Y200810)
文摘As a pivotal signal pathway,the Ras/Raf/MEK/ERK cascade can be activated by multiple extracellular stimuli and can transmit signals to diverse substrates.It remains to be elucidated how so many different signals can be variously transferred by only two MEK molecules(MEK1 and MEK2) .Because of technological limitations the complete structures of the MEKs are still unavailable.Here,we report the full-length structure of MEK2 obtained by homology modeling and molecular dynamics simulations.The simulations show that the N-terminal part of MEK2 is highly flexible and this flexibility may enable MEK2 to interact with ERKs and other ligands in diverse manners that correspond to various upstream signals and downstream consequences.
