In this study,two indica varieties with different dormancy characteristics [4 K58( II-32 B dormant),4 K59( II-32 B) ] and their F2 seeds( C178,C179) obtained through hybridization with sterile line( II-32 A) were used...In this study,two indica varieties with different dormancy characteristics [4 K58( II-32 B dormant),4 K59( II-32 B) ] and their F2 seeds( C178,C179) obtained through hybridization with sterile line( II-32 A) were used as materials. Different aged seeds( 0,3,6 and 9 d) of these four varieties were acquired by artificial accelerated aging method. Effects of artificial aging on malondialdehyde( MDA) content and catalase( CAT),ascorbate peroxidase( APX),peroxidase( POD) and superoxide dismutase( SOD) activity were investigated. The results showed that with the prolongation of aging time,MDA contents of these four rice varieties increased significantly,while the activity of antioxidant enzymes decreased dramatically. Besides,MDA contents and SOD,CAT and APX activity of the two inbred lines were significantly lower than those of the hybrid varieties. In addition,the activity of antioxidant enzymes in 4 K58 and C178 was significantly lower than that in 4 K59 and C179,respectively. This study indicated that artificial aging treatment significantly inhibited the activity of antioxidant system in seeds,improved membrane lipid peroxidation degree,and thus aggravated the deterioration of seeds. In addition,it also suggested that rice seeds with dormant property were more intolerant to storage.展开更多
The identification of highly active heterogeneous catalysts to replace their homogeneous counterparts remains a challenge in the case of organic catalysts, especially polymers, in highly viscous reaction systems. In t...The identification of highly active heterogeneous catalysts to replace their homogeneous counterparts remains a challenge in the case of organic catalysts, especially polymers, in highly viscous reaction systems. In this work, we designed and synthesized a novel, solid-supported, and heterogeneous pseudo-single atom Pt catalyst with high activity and recyclability. Superparamagnetic Fe3O4-SiO2 core--shell nanoparticles （NPs） were used as the substrate. The functionalization of the SiO2 shell with silane coupling agents containing vinyl groups allows stabilizing Pt on the SiO2 surface through complexation. The as-prepared pseudosingle atom Pt displays high activity in the hydrosilylation of allyl-terminated polyether with polymethylhydrosiloxane and could be easily collected by applying a magnetic field. The Pt/vinyl/SiO2/Fe3O4 catalyst can be reused for up to four reaction cycles without appreciable decrease in activity. This work demonstrates a novel strategy for the design of pseudo-single atom noble metal catalysts for processes in high-viscosity media.展开更多
Brain science accelerates the study of intelligence and behavior,contributes fundamental insights into human cognition,and offers prospective treatments for brain disease.Faced with the challenges posed by imaging tec...Brain science accelerates the study of intelligence and behavior,contributes fundamental insights into human cognition,and offers prospective treatments for brain disease.Faced with the challenges posed by imaging technologies and deep learning computational models,big data and high-performance computing(HPC)play essential roles in studying brain function,brain diseases,and large-scale brain models or connectomes.We review the driving forces behind big data and HPC methods applied to brain science,including deep learning,powerful data analysis capabilities,and computational performance solutions,each of which can be used to improve diagnostic accuracy and research output.This work reinforces predictions that big data and HPC will continue to improve brain science by making ultrahigh-performance analysis possible,by improving data standardization and sharing,and by providing new neuromorphic insights.展开更多
基金Supported by National Key Research and Development Project(2018YFD0101000)
文摘In this study,two indica varieties with different dormancy characteristics [4 K58( II-32 B dormant),4 K59( II-32 B) ] and their F2 seeds( C178,C179) obtained through hybridization with sterile line( II-32 A) were used as materials. Different aged seeds( 0,3,6 and 9 d) of these four varieties were acquired by artificial accelerated aging method. Effects of artificial aging on malondialdehyde( MDA) content and catalase( CAT),ascorbate peroxidase( APX),peroxidase( POD) and superoxide dismutase( SOD) activity were investigated. The results showed that with the prolongation of aging time,MDA contents of these four rice varieties increased significantly,while the activity of antioxidant enzymes decreased dramatically. Besides,MDA contents and SOD,CAT and APX activity of the two inbred lines were significantly lower than those of the hybrid varieties. In addition,the activity of antioxidant enzymes in 4 K58 and C178 was significantly lower than that in 4 K59 and C179,respectively. This study indicated that artificial aging treatment significantly inhibited the activity of antioxidant system in seeds,improved membrane lipid peroxidation degree,and thus aggravated the deterioration of seeds. In addition,it also suggested that rice seeds with dormant property were more intolerant to storage.
基金This work is partially supported by the National Natural Science Foundation of China （No. 21303265） and Ph.D. Programs Foundation of Ministry of Education of China （No. 20130007120012）.
文摘The identification of highly active heterogeneous catalysts to replace their homogeneous counterparts remains a challenge in the case of organic catalysts, especially polymers, in highly viscous reaction systems. In this work, we designed and synthesized a novel, solid-supported, and heterogeneous pseudo-single atom Pt catalyst with high activity and recyclability. Superparamagnetic Fe3O4-SiO2 core--shell nanoparticles （NPs） were used as the substrate. The functionalization of the SiO2 shell with silane coupling agents containing vinyl groups allows stabilizing Pt on the SiO2 surface through complexation. The as-prepared pseudosingle atom Pt displays high activity in the hydrosilylation of allyl-terminated polyether with polymethylhydrosiloxane and could be easily collected by applying a magnetic field. The Pt/vinyl/SiO2/Fe3O4 catalyst can be reused for up to four reaction cycles without appreciable decrease in activity. This work demonstrates a novel strategy for the design of pseudo-single atom noble metal catalysts for processes in high-viscosity media.
基金supported by the National Natural Science Foundation of China(Grant No.31771466)the National Key R&D Program of China(Grant Nos.2018YFB0203903,2016YFC0503607,and 2016YFB0200300)+3 种基金the Transformation Project in Scientific and Technological Achievements of Qinghai,China(Grant No.2016-SF-127)the Special Project of Informatization of Chinese Academy of Sciences,China(Grant No.XXH13504-08)the Strategic Pilot Science and Technology Project of Chinese Academy of Sciences,China(Grant No.XDA12010000)the 100-Talents Program of Chinese Academy of Sciences,China(awarded to BN)
文摘Brain science accelerates the study of intelligence and behavior,contributes fundamental insights into human cognition,and offers prospective treatments for brain disease.Faced with the challenges posed by imaging technologies and deep learning computational models,big data and high-performance computing(HPC)play essential roles in studying brain function,brain diseases,and large-scale brain models or connectomes.We review the driving forces behind big data and HPC methods applied to brain science,including deep learning,powerful data analysis capabilities,and computational performance solutions,each of which can be used to improve diagnostic accuracy and research output.This work reinforces predictions that big data and HPC will continue to improve brain science by making ultrahigh-performance analysis possible,by improving data standardization and sharing,and by providing new neuromorphic insights.
