In rice, amylose content （AC） is controlled by a single dominant Waxy gene. We used Clustered Regularly Interspaced Short Palindromic Repeats （CRISPR）/CRISPR-associated 9 （Casg） to introduce a loss-of-function m...In rice, amylose content （AC） is controlled by a single dominant Waxy gene. We used Clustered Regularly Interspaced Short Palindromic Repeats （CRISPR）/CRISPR-associated 9 （Casg） to introduce a loss-of-function mutation into the Waxy gene in two widely cultivated elite japonica varieties. Our results show that mutations in the Waxy gene reduce AC and convert the rice into glutinous ones without affecting other desirable agronomic traits, offering an effective and easy strategy to improve glutinosity in elite varieties. Importantly, we successfully removed the transgenes from the progeny. Our study provides an example of generating improved crops with potential for commercialization, by editing a gene of interest directly in elite crop varieties.展开更多
Background:As reported by the World Health Organization,a novel coronavirus(2019-nCoV)was identified as the causative virus of Wuhan pneumonia of unknown etiology by Chinese authorities on 7 January,2020.The virus was...Background:As reported by the World Health Organization,a novel coronavirus(2019-nCoV)was identified as the causative virus of Wuhan pneumonia of unknown etiology by Chinese authorities on 7 January,2020.The virus was named as severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)by International Committee on Taxonomy of Viruses on 11 February,2020.This study aimed to develop a mathematical model for calculating the transmissibility of the virus.Methods:In this study,we developed a Bats-Hosts-Reservoir-People transmission network model for simulating the potential transmission from the infection source(probably be bats)to the human infection.Since the Bats-HostsReservoir network was hard to explore clearly and public concerns were focusing on the transmission from Huanan Seafood Wholesale Market(reservoir)to people,we simplified the model as Reservoir-People(RP)transmission network model.The next generation matrix approach was adopted to calculate the basic reproduction number(R0)from the RP model to assess the transmissibility of the SARS-CoV-2.Results:The value of R0 was estimated of 2.30 from reservoir to person and 3.58 from person to person which means that the expected number of secondary infections that result from introducing a single infected individual into an otherwise susceptible population was 3.58.Conclusions:Our model showed that the transmissibility of SARS-CoV-2 was higher than the Middle East respiratory syndrome in the Middle East countries,similar to severe acute respiratory syndrome,but lower than MERS in the Republic of Korea.展开更多
Lithium-ion power battery has become one of the main power sources for electric vehicles and hybrid electric vehicles because of superior performance compared with other power sources. In order to ensure the safety an...Lithium-ion power battery has become one of the main power sources for electric vehicles and hybrid electric vehicles because of superior performance compared with other power sources. In order to ensure the safety and improve the performance, the maximum operating temperature and local temperature difference of batteries must be maintained in an appropriate range. The effect of temperature on the capacity fade and aging are simply investigated. The electrode structure, including electrode thickness, particle size and porosity, are analyzed. It is found that all of them have significant influences on the heat generation of battery. Details of various thermal management technologies, namely air based, phase change material based, heat pipe based and liquid based, are discussed and compared from the perspective of improving the external heat dissipation. The selection of different battery thermal management(BTM) technologies should be based on the cooling demand and applications, and liquid cooling is suggested being the most suitable method for large-scale battery pack charged/discharged at higher C-rate and in high-temperature environment. The thermal safety in the respect of propagation and suppression of thermal runaway is analyzed.展开更多
基金supported by the Chinese Academy of SciencesUS NIH Grants R01GM070795 and R01GM059138(to J.K.Z.)the support of the International Postdoctoral Exchange Fellowship Program of China under grant 20140029
文摘In rice, amylose content （AC） is controlled by a single dominant Waxy gene. We used Clustered Regularly Interspaced Short Palindromic Repeats （CRISPR）/CRISPR-associated 9 （Casg） to introduce a loss-of-function mutation into the Waxy gene in two widely cultivated elite japonica varieties. Our results show that mutations in the Waxy gene reduce AC and convert the rice into glutinous ones without affecting other desirable agronomic traits, offering an effective and easy strategy to improve glutinosity in elite varieties. Importantly, we successfully removed the transgenes from the progeny. Our study provides an example of generating improved crops with potential for commercialization, by editing a gene of interest directly in elite crop varieties.
基金This study was supported by Xiamen New Coronavirus Prevention and Control Emergency Tackling Special Topic Program(No:3502Z2020YJ03).
文摘Background:As reported by the World Health Organization,a novel coronavirus(2019-nCoV)was identified as the causative virus of Wuhan pneumonia of unknown etiology by Chinese authorities on 7 January,2020.The virus was named as severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)by International Committee on Taxonomy of Viruses on 11 February,2020.This study aimed to develop a mathematical model for calculating the transmissibility of the virus.Methods:In this study,we developed a Bats-Hosts-Reservoir-People transmission network model for simulating the potential transmission from the infection source(probably be bats)to the human infection.Since the Bats-HostsReservoir network was hard to explore clearly and public concerns were focusing on the transmission from Huanan Seafood Wholesale Market(reservoir)to people,we simplified the model as Reservoir-People(RP)transmission network model.The next generation matrix approach was adopted to calculate the basic reproduction number(R0)from the RP model to assess the transmissibility of the SARS-CoV-2.Results:The value of R0 was estimated of 2.30 from reservoir to person and 3.58 from person to person which means that the expected number of secondary infections that result from introducing a single infected individual into an otherwise susceptible population was 3.58.Conclusions:Our model showed that the transmissibility of SARS-CoV-2 was higher than the Middle East respiratory syndrome in the Middle East countries,similar to severe acute respiratory syndrome,but lower than MERS in the Republic of Korea.
基金Supported by National Natural Science Foundation of China(No.51376019)
文摘Lithium-ion power battery has become one of the main power sources for electric vehicles and hybrid electric vehicles because of superior performance compared with other power sources. In order to ensure the safety and improve the performance, the maximum operating temperature and local temperature difference of batteries must be maintained in an appropriate range. The effect of temperature on the capacity fade and aging are simply investigated. The electrode structure, including electrode thickness, particle size and porosity, are analyzed. It is found that all of them have significant influences on the heat generation of battery. Details of various thermal management technologies, namely air based, phase change material based, heat pipe based and liquid based, are discussed and compared from the perspective of improving the external heat dissipation. The selection of different battery thermal management(BTM) technologies should be based on the cooling demand and applications, and liquid cooling is suggested being the most suitable method for large-scale battery pack charged/discharged at higher C-rate and in high-temperature environment. The thermal safety in the respect of propagation and suppression of thermal runaway is analyzed.
