Starting from December 2019,Wuhan,China,encountered the first outbreak of coronavirus disease 2019(COVID-19)(1-2).The epidemic was successfully suppressed by strict containment so that the number of infected people wa...Starting from December 2019,Wuhan,China,encountered the first outbreak of coronavirus disease 2019(COVID-19)(1-2).The epidemic was successfully suppressed by strict containment so that the number of infected people was reduced to 0 on April 8,2020(3–4).After that,China experienced roughly 3 dozen outbreaks with local transmission caused by imported severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).展开更多
The basic biomechanical laws that apply to the clawed toes of animals with powerful digging abilities and the optimal bionic design of curved soil cultivating components with an analogous contour were researched in a ...The basic biomechanical laws that apply to the clawed toes of animals with powerful digging abilities and the optimal bionic design of curved soil cultivating components with an analogous contour were researched in a novel way. First, the curvature and profile of the inside contour line of a field mouse’s clawed toe were analyzed. The finite element method (FEM) was then used to simulate the working process in order to study the changing characteristics of the working resistance of bionic soil- engag- ing surfaces and the stress field of the processed soil. A straight-line cultivating component was used for comparative analysis. In accordance with the simulation results, a series of soil cultivating com- ponents of varying design were manufactured. An indoor soil bin experiment was carried out to meas- ure their working resistance and validate the results of the FEM analysis. The results of this research would have important values in the optimization design of cultivating components for energy and cost savings.展开更多
The coronavirus disease 2019(COVID-19)pandemic is caused by infection with the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),which is spread primary via respiratory droplets and infects the lungs.Current...The coronavirus disease 2019(COVID-19)pandemic is caused by infection with the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),which is spread primary via respiratory droplets and infects the lungs.Currently widely used cell lines and animals are unable to accurately mimic human physiological conditions because of the abnormal status of cell lines(transformed or cancer cells)and species differences between animals and humans.Organoids are stem cell-derived selforganized three-dimensional culture in vitro and model the physiological conditions of natural organs.Here we showed that SARS-CoV-2 infected and extensively replicated in human embryonic stem cells(hESCs)-derived lung organoids,including airway and alveolar organoids which covered the complete infection and spread route for SARS-CoV-2 within lungs.The infected ceils were ciliated,club,and alveolar type 2(AT2)cells,which were sequentially located from the proximal to the distal airway and terminal alveoli,respectively.Additionally,RNA-seq revealed early cell response to virus infection including an unexpected downregulation of the metabolic processes,especially lipid metabolism,in addition to the well-known upregulation of immune response.Further,Remdesivir and a human neutralizing antibody potently inhibited SARS-CoV-2 replication in lung organoids.Therefore,human lung organoids can serve as a pathophysiological model to investigate the underlying mechanism of SARS-CoV-2 infection and to discover and test therapeutic drugs for COVID-19.展开更多
基金Supported by the National Natural Science Foundation(grant number 71934002)of the People’s Republic of China.
文摘Starting from December 2019,Wuhan,China,encountered the first outbreak of coronavirus disease 2019(COVID-19)(1-2).The epidemic was successfully suppressed by strict containment so that the number of infected people was reduced to 0 on April 8,2020(3–4).After that,China experienced roughly 3 dozen outbreaks with local transmission caused by imported severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).
基金Supported by the Scientific and Technological Project from the Science and Tech-nology Office of Henan Province, China (Grant Nos. 0424220152 and 0623021300)
文摘The basic biomechanical laws that apply to the clawed toes of animals with powerful digging abilities and the optimal bionic design of curved soil cultivating components with an analogous contour were researched in a novel way. First, the curvature and profile of the inside contour line of a field mouse’s clawed toe were analyzed. The finite element method (FEM) was then used to simulate the working process in order to study the changing characteristics of the working resistance of bionic soil- engag- ing surfaces and the stress field of the processed soil. A straight-line cultivating component was used for comparative analysis. In accordance with the simulation results, a series of soil cultivating com- ponents of varying design were manufactured. An indoor soil bin experiment was carried out to meas- ure their working resistance and validate the results of the FEM analysis. The results of this research would have important values in the optimization design of cultivating components for energy and cost savings.
基金This work was supported by grants from National Natural Science Foundation of China(Grant Nos.82070002,82072329,81872511,and 81670093)Frontier Research Program of Bioland Laboratory(Guangzhou Regenerative Medicine and Health Guangdong Laboratory)(2018GZR110105005)+6 种基金National Science and Technology Major Project(2018ZX10301101)the Natural Science Foundation of Guangdong Province(2018A030313455)the Program of Department of Science and Technology of Guangdong Province(2014B020212018)National Key Research and Development Project(2018YFA0507201)the special project for COVID-19 of Guangzhou Regenerative Medicine and Health Guangdong Labo・ratory(2020GZR110106006)the emergency grants for prevention and control of SARS-CoV-2 of Guangdong province(2020B111108001)National Postdoctoral Program for Innovative Talent(BX20190089).
文摘The coronavirus disease 2019(COVID-19)pandemic is caused by infection with the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),which is spread primary via respiratory droplets and infects the lungs.Currently widely used cell lines and animals are unable to accurately mimic human physiological conditions because of the abnormal status of cell lines(transformed or cancer cells)and species differences between animals and humans.Organoids are stem cell-derived selforganized three-dimensional culture in vitro and model the physiological conditions of natural organs.Here we showed that SARS-CoV-2 infected and extensively replicated in human embryonic stem cells(hESCs)-derived lung organoids,including airway and alveolar organoids which covered the complete infection and spread route for SARS-CoV-2 within lungs.The infected ceils were ciliated,club,and alveolar type 2(AT2)cells,which were sequentially located from the proximal to the distal airway and terminal alveoli,respectively.Additionally,RNA-seq revealed early cell response to virus infection including an unexpected downregulation of the metabolic processes,especially lipid metabolism,in addition to the well-known upregulation of immune response.Further,Remdesivir and a human neutralizing antibody potently inhibited SARS-CoV-2 replication in lung organoids.Therefore,human lung organoids can serve as a pathophysiological model to investigate the underlying mechanism of SARS-CoV-2 infection and to discover and test therapeutic drugs for COVID-19.
