"Synthetic"allopolyploids recreated by interspecific hybridization play an important role in providing novel genomic variation for crop improvement.Such synthetic allopolyploids often undergo rapid genomic s..."Synthetic"allopolyploids recreated by interspecific hybridization play an important role in providing novel genomic variation for crop improvement.Such synthetic allopolyploids often undergo rapid genomic structural variation(SV).However,how such SV arises,is inherited and fixed,and how it affects important traits,has rarely been comprehensively and quantitively studied in advanced generation synthetic lines.A better understanding of these processes will aid breeders in knowing how to best utilize synthetic allopolyploids in breeding programs.Here,we analyzed three genetic mapping populations(735 DH lines)derived from crosses between advanced synthetic and conventional Brassica napus(rapeseed)lines,using whole-genome sequencing to determine genome composition.We observed high tolerance of large structural variants,particularly toward the telomeres,and preferential selection for balanced homoeologous exchanges(duplication/deletion events between the A and C genomes resulting in retention of gene/chromosome dosage between homoeologous chromosome pairs),including stable events involving whole chromosomes("pseudoeuploidy").Given the experimental design(all three populations shared a common parent),we were able to observe that parental SV was regularly inherited,showed genetic hitchhiking effects on segregation,and was one of the major factors inducing adjacent novel and larger SV.Surprisingly,novel SV occurred at low frequencies with no significant impacts on observed fertility and yield-related traits in the advanced generation synthetic lines.However,incorporating genome-wide SV in linkage mapping explained significantly more genetic variance for traits.Our results provide a framework for detecting and understanding the occurrence and inheritance of genomic SV in breeding programs,and support the use of synthetic parents as an important source of novel trait variation.展开更多
Copper is an indispensable trace metal element in the human body,which is mainly absorbed in the stomach and small intestine and excreted into the bile.Copper is an important component and catalytic agent of many enzy...Copper is an indispensable trace metal element in the human body,which is mainly absorbed in the stomach and small intestine and excreted into the bile.Copper is an important component and catalytic agent of many enzymes and proteins in the body,so it can influence human health through multiple mechanisms.Based on the biological functions and benefits of copper,an increasing number of researchers in the field of biomaterials have focused on developing novel copper-containing biomaterials,which exhibit unique properties in protecting the cardiovascular system,promoting bone fracture healing,and exerting antibacterial effects.Copper can also be used in promoting incisional wounds healing,killing cancer cells,Positron Emission Tomography(PET)imaging,radioimmunological tracing and radiotherapy of cancer.In the present review,the biological functions of copper in the human body are presented,along with an overview of recent progress in our understanding of the biological applications and development of copper-containing materials.Furthermore,this review also provides the prospective on the challenges of those novel biomaterials for future clinical applications.展开更多
The need to simultaneously balance security and fairness in quantum key agreement(QKA) makes it challenging to design a flawless QKA protocol, especially a multiparty quantum key agreement(MQKA) protocol. When designi...The need to simultaneously balance security and fairness in quantum key agreement(QKA) makes it challenging to design a flawless QKA protocol, especially a multiparty quantum key agreement(MQKA) protocol. When designing an MQKA protocol,two modes can be used to transmit the quantum information carriers: travelling mode and distributed mode. MQKA protocols usually have a higher qubit efficiency in travelling mode than in distributed mode. Thus, several travelling mode MQKA protocols have been proposed. However, almost all of these are vulnerable to collusion attacks from internal betrayers. This paper proposes an improved MQKA protocol that operates in travelling mode with Einstein-Podolsky-Rosen pairs. More importantly, we present a new travelling mode MQKA protocol that uses single photons, which is more feasible than previous methods under current technologies.展开更多
The new land observation satellite Sentinel-1A was launched on 25 April 2014 with a C-band synthetic aperture radar(SAR)sensor,which has the significant enhancements in terms of revisit period and high resolution.The ...The new land observation satellite Sentinel-1A was launched on 25 April 2014 with a C-band synthetic aperture radar(SAR)sensor,which has the significant enhancements in terms of revisit period and high resolution.The Mw 6.1 Napa,California earthquake occurring on 24 August 2014,almost 4 months after the launch,is the first moderate earthquake imaged by the Sentinel-1A.This provides an opportunity to map the coseismic deformation of the event and evaluate the potential of Sentinel-1A SAR for earthquake study.Two techniques including the interferometric SAR(InSAR)and pixel offset-tracking(PO)are,respectively,employed to map the surface deformation along the radar line of sight(LOS),azimuth and slant-range directions.The cross comparison between Sentinel-1A InSAR LOS deformation and GPS observations indicates good agreement with an accuracy of∼2.6 mm.We further estimate the earthquake source model with the external COSMO-SkyMed InSAR and GPS data as constraints,and forward calculate the surface deformation as cross validation with the Sentinel-1A observations.The comparison between the observed and modeled deformation shows that the Sentinel-1A measurement accuracy can achieve 1.6 cm for InSAR technique along LOS direction,and 6.3 and 6.7 cm for PO along azimuth and range directions,respectively.展开更多
基金supported by the National Natural Science Foundation of China(NSFC,31970564,32000397,32171982)the Fundamental Research Funds for the Central Universities(2662023PY004)。
文摘"Synthetic"allopolyploids recreated by interspecific hybridization play an important role in providing novel genomic variation for crop improvement.Such synthetic allopolyploids often undergo rapid genomic structural variation(SV).However,how such SV arises,is inherited and fixed,and how it affects important traits,has rarely been comprehensively and quantitively studied in advanced generation synthetic lines.A better understanding of these processes will aid breeders in knowing how to best utilize synthetic allopolyploids in breeding programs.Here,we analyzed three genetic mapping populations(735 DH lines)derived from crosses between advanced synthetic and conventional Brassica napus(rapeseed)lines,using whole-genome sequencing to determine genome composition.We observed high tolerance of large structural variants,particularly toward the telomeres,and preferential selection for balanced homoeologous exchanges(duplication/deletion events between the A and C genomes resulting in retention of gene/chromosome dosage between homoeologous chromosome pairs),including stable events involving whole chromosomes("pseudoeuploidy").Given the experimental design(all three populations shared a common parent),we were able to observe that parental SV was regularly inherited,showed genetic hitchhiking effects on segregation,and was one of the major factors inducing adjacent novel and larger SV.Surprisingly,novel SV occurred at low frequencies with no significant impacts on observed fertility and yield-related traits in the advanced generation synthetic lines.However,incorporating genome-wide SV in linkage mapping explained significantly more genetic variance for traits.Our results provide a framework for detecting and understanding the occurrence and inheritance of genomic SV in breeding programs,and support the use of synthetic parents as an important source of novel trait variation.
基金The authors acknowledge financial support from National Natural Science Foundation of China(Nos.81873918,51631009)Construction Project of Liaoning Medical Imaging and Interventional Medical Engineering Research Center(Grant No.18-006-9-01)Key Research and Serving Local Area Projects of the Educational Department of Liaoning Province,China(Grant No.ZF2019005).
文摘Copper is an indispensable trace metal element in the human body,which is mainly absorbed in the stomach and small intestine and excreted into the bile.Copper is an important component and catalytic agent of many enzymes and proteins in the body,so it can influence human health through multiple mechanisms.Based on the biological functions and benefits of copper,an increasing number of researchers in the field of biomaterials have focused on developing novel copper-containing biomaterials,which exhibit unique properties in protecting the cardiovascular system,promoting bone fracture healing,and exerting antibacterial effects.Copper can also be used in promoting incisional wounds healing,killing cancer cells,Positron Emission Tomography(PET)imaging,radioimmunological tracing and radiotherapy of cancer.In the present review,the biological functions of copper in the human body are presented,along with an overview of recent progress in our understanding of the biological applications and development of copper-containing materials.Furthermore,this review also provides the prospective on the challenges of those novel biomaterials for future clinical applications.
基金supported by the National Natural Science Foundation of China(Grant Nos.61501414,61602045,61601171,61309029,11504024 and 61502041)
文摘The need to simultaneously balance security and fairness in quantum key agreement(QKA) makes it challenging to design a flawless QKA protocol, especially a multiparty quantum key agreement(MQKA) protocol. When designing an MQKA protocol,two modes can be used to transmit the quantum information carriers: travelling mode and distributed mode. MQKA protocols usually have a higher qubit efficiency in travelling mode than in distributed mode. Thus, several travelling mode MQKA protocols have been proposed. However, almost all of these are vulnerable to collusion attacks from internal betrayers. This paper proposes an improved MQKA protocol that operates in travelling mode with Einstein-Podolsky-Rosen pairs. More importantly, we present a new travelling mode MQKA protocol that uses single photons, which is more feasible than previous methods under current technologies.
基金This work was supported by the National Natural Science Foundation of China[grant numbers 41472255,51178404].
文摘The new land observation satellite Sentinel-1A was launched on 25 April 2014 with a C-band synthetic aperture radar(SAR)sensor,which has the significant enhancements in terms of revisit period and high resolution.The Mw 6.1 Napa,California earthquake occurring on 24 August 2014,almost 4 months after the launch,is the first moderate earthquake imaged by the Sentinel-1A.This provides an opportunity to map the coseismic deformation of the event and evaluate the potential of Sentinel-1A SAR for earthquake study.Two techniques including the interferometric SAR(InSAR)and pixel offset-tracking(PO)are,respectively,employed to map the surface deformation along the radar line of sight(LOS),azimuth and slant-range directions.The cross comparison between Sentinel-1A InSAR LOS deformation and GPS observations indicates good agreement with an accuracy of∼2.6 mm.We further estimate the earthquake source model with the external COSMO-SkyMed InSAR and GPS data as constraints,and forward calculate the surface deformation as cross validation with the Sentinel-1A observations.The comparison between the observed and modeled deformation shows that the Sentinel-1A measurement accuracy can achieve 1.6 cm for InSAR technique along LOS direction,and 6.3 and 6.7 cm for PO along azimuth and range directions,respectively.