Bi_(2)Te_(3) based alloys have been the most widely used thermoelectric material at low temperature for many decades.Here we report Se doped n-type Mg_(3)Bi_(2) based materials with a thermoelectric figure-of-merit ZT...Bi_(2)Te_(3) based alloys have been the most widely used thermoelectric material at low temperature for many decades.Here we report Se doped n-type Mg_(3)Bi_(2) based materials with a thermoelectric figure-of-merit ZT of 0.82 at 300 K and a peak ZT of 1.24 at 498 K,which is comparable to the n-type Bi_(2)Te_(3) and Te doped Mg_(3)Bi_(1.4)Sb_(0.6).The improved thermoelectric performance is benefited from the high carrier concentration and mobility as well as the thermal conductivity reduction.The reduced resistivity increased the power factor at all measured temperatures,leading to a higher engineering ZT(ZTeng)and engineering power factor(PFeng)for n-type Mg_(3)Bi_(2).The n-type Mg_(3)Bi_(1.4)Sb_(0.6) materials are promising for thermoelectric power generation and cooling applications near room temperature.展开更多
Mg_(3)Sb_(1.5)Bi_(0.5)-based Zintl compounds have attracted extensive attention as potential thermoelectric materials due to their earth-abundant elements.However,pure and intrinsic Mg_(3)Sb_(1.5)Bi_(0.5)manifests a p...Mg_(3)Sb_(1.5)Bi_(0.5)-based Zintl compounds have attracted extensive attention as potential thermoelectric materials due to their earth-abundant elements.However,pure and intrinsic Mg_(3)Sb_(1.5)Bi_(0.5)manifests a poor thermoelectric performance because of its low electrical conductivity of about 3×10^(2)S/m at room temperature.In this work,In and Se co-doping was carried out to optimize the thermoelectric perfor-mance of n-type Mg_(3)Sb_(1.5)Bi_(0.5)-based material.The experimental results revealed that the carrier con-centration and mobility of Mg_(3)Sb_(1.5)Bi_(0.5)significantly increased after In and Se co-doping,leading to an improvement of power factor.Simultaneously,lattice thermal conductivity was significantly reduced due to the large mass difference between In and Mg.A maximum zT of 1.64 at 723 K was obtained for the Mg_(3.17)In_(0.03)Sb_(1.5)Bi_(0.49)Se_(0.01)sample.And an average zT value of about 1.1 between 300 and 723 K was achieved,which insures its possible application at medium temperature range as a non-toxic and low-cost TE material.展开更多
Dear Editor,To date,seven human coronaviruses(HCoVs)have been identified,among which the highly pathogenic severe acute respiratory syndrome-associated coronavirus(SARS-CoV),Middle East respiratory syndrome coronaviru...Dear Editor,To date,seven human coronaviruses(HCoVs)have been identified,among which the highly pathogenic severe acute respiratory syndrome-associated coronavirus(SARS-CoV),Middle East respiratory syndrome coronavirus(MERS-CoV),and severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)have caused public health disasters worldwide.展开更多
The coronavirus disease 2019(COVID-19)pandemic has devastated global health.Identifying key host factors essential for SARS-CoV-2 RNA replication is expected to unravel cellular targets for the development of broad-sp...The coronavirus disease 2019(COVID-19)pandemic has devastated global health.Identifying key host factors essential for SARS-CoV-2 RNA replication is expected to unravel cellular targets for the development of broad-spectrum antiviral drugs which have been quested for the preparedness of future viral outbreaks.Here,we have identified host proteins that associate with nonstructural protein 12(nsp12),the RNA-dependent RNA polymerase(RdRp)of SARS-CoV-2 using a mass spectrometry(MS)-based proteomic approach.Among the candidate factors,CDK2(Cyclin-dependent kinase 2),a member of cyclin-dependent kinases,interacts with nsp12 and causes its phosphorylation at T20,thus facilitating the assembly of the RdRp complex consisting of nsp12,nsp7 and nsp8 and promoting efficient synthesis of viral RNA.The crucial role of CDK2 in viral RdRp function is further supported by our observation that CDK2 inhibitors potently impair viral RNA synthesis and SARS-CoV-2 infection.Taken together,we have discovered CDK2 as a key host factor of SARS-CoV-2 RdRp complex,thus serving a promising target for the development of SARS-CoV-2 RdRp inhibitors.展开更多
SARS-CoV-2 is the pathogenic agent of COVID-19,which has evolved into a global pandemic.Compared with some other respiratory RNA viruses,SARS-CoV-2 is a poor inducer of type Ⅰ interferon(IFN).Here,we report that SARS...SARS-CoV-2 is the pathogenic agent of COVID-19,which has evolved into a global pandemic.Compared with some other respiratory RNA viruses,SARS-CoV-2 is a poor inducer of type Ⅰ interferon(IFN).Here,we report that SARS-CoV-2 nsp12,the viral RNA-dependent RNA polymerase(RdRp),suppresses host antiviral responses.SARS-CoV-2 nsp12 attenuated Sendai virus(SeV)-or poly(I:C)-induced IFN-β promoter activation in a dose-dependent manner.It also inhibited IFN promoter activation triggered by RIG-I,MDA5,MAVS,and IRF3 overexpression.Nsp12 did not impair IRF3 phosphorylation but suppressed the nuclear translocation of IRF3.Mutational analyses suggested that this suppression was not dependent on the polymerase activity of nsp12.Given these findings,our study reveals that SARS-CoV-2 RdRp can antagonize host antiviral innate immunity and thus provides insights into viral pathogenesis.展开更多
Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has caused a devastating pandemic worldwide.Vaccines and antiviral drugs are the most promising candidates for combating this global epidemic,and scientists a...Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has caused a devastating pandemic worldwide.Vaccines and antiviral drugs are the most promising candidates for combating this global epidemic,and scientists all over the world have made great efforts to this end.However,manipulation of the SARS-CoV-2 should be performed in the biosafety level3 laboratory.This makes experiments complicated and time-consuming.Therefore,a safer system for working with this virus is urgently needed.Here,we report the construction of plasmid-based,non-infectious SARS-CoV-2 replicons with turbo-green fluorescent protein and/or firefly luciferase reporters by reverse genetics using transformation-associated recombination cloning in Saccharomyces cerevisiae.Replication of these replicons was achieved simply by direct transfection of cells with the replicon plasmids as evident by the expression of reporter genes.Using SARS-CoV-2 replicons,the inhibitory effects of E64-D and remdesivir on SARS-CoV-2 replication were confirmed,and the halfmaximal effective concentration(EC50)value of remdesivir and E64-D was estimated by different quantification methods respectively,indicating that these SARS-CoV-2 replicons are useful tools for antiviral drug evaluation.展开更多
Severe acute respiratory syndrome coronavirus-2(SARS-CoV-2) has become one major threat to human population health.The RNA-dependent RNA polymerase(RdRp) presents an ideal target of antivirals,whereas nucleoside analo...Severe acute respiratory syndrome coronavirus-2(SARS-CoV-2) has become one major threat to human population health.The RNA-dependent RNA polymerase(RdRp) presents an ideal target of antivirals,whereas nucleoside analogs inhibitor is hindered by the proofreading activity of coronavirus.Herein,we report that corilagin(RAI-S-37) as a non-nucleoside inhibitor of SARS-CoV-2 RdRp,binds directly to RdRp,effectively inhibits the polymerase activity in both cell-free and cell-based assays,fully resists the proofreading activity and potently inhibits SARS-CoV-2 infection with a low 50% effective concentration(EC50) value of 0.13 μmol/L.Computation modeling predicts that RAI-S-37 lands at the palm domain of RdRp and prevents conformational changes required for nucleotide incorporation by RdRp.In addition,combination of RAI-S-37 with remdesivir exhibits additive activity against antiSARS-CoV-2 RdRp.Together with the current data available on the safety and pharmacokinetics of corilagin as a medicinal herbal agent,these results demonstrate the potential of being developed into one of the much-needed SARS-CoV-2 therapeutics.展开更多
The global coronavirus disease 2019(COVID-19)pandemic is caused by severe acute respiratory syndrome coronavirus 2(SARSCoV-2),a positive-sense RNA virus.How the host immune system senses and responds to SARS-CoV-2 inf...The global coronavirus disease 2019(COVID-19)pandemic is caused by severe acute respiratory syndrome coronavirus 2(SARSCoV-2),a positive-sense RNA virus.How the host immune system senses and responds to SARS-CoV-2 infection remain largely unresolved.Here,we report that SARS-CoV-2 infection activates the innate immune response through the cytosolic DNA sensing cGAS-STING pathway.SARS-CoV-2 infection induces the cellular level of 2′3′-cGAMP associated with STING activation.cGAS recognizes chromatin DNA shuttled from the nucleus as a result of cell-to-cell fusion upon SARS-CoV-2 infection.We further demonstrate that the expression of spike protein from SARS-CoV-2 and ACE2 from host cells is sufficient to trigger cytoplasmic chromatin upon cell fusion.Furthermore,cytoplasmic chromatin-cGAS-STING pathway,but not MAVS-mediated viral RNA sensing pathway,contributes to interferon and pro-inflammatory gene expression upon cell fusion.Finally,we show that cGAS is required for host antiviral responses against SARS-CoV-2,and a STING-activating compound potently inhibits viral replication.Together,our study reported a previously unappreciated mechanism by which the host innate immune system responds to SARS-CoV-2 infection,mediated by cytoplasmic chromatin from the infected cells.Targeting the cytoplasmic chromatin-cGAS-STING pathway may offer novel therapeutic opportunities in treating COVID-19.In addition,these findings extend our knowledge in host defense against viral infection by showing that host cells’self-nucleic acids can be employed as a“danger signal”to alarm the immune system.展开更多
Severe acute respiratory syndrome coronavirus 2(SARS‐CoV‐2)continues to evolve,generating new variants that pose a threat to global health;therefore,it is imperative to obtain safe and broad‐spectrum antivirals aga...Severe acute respiratory syndrome coronavirus 2(SARS‐CoV‐2)continues to evolve,generating new variants that pose a threat to global health;therefore,it is imperative to obtain safe and broad‐spectrum antivirals against SARS‐CoV‐2 and its variants.To this end,we screened compounds for their ability to inhibit viral entry,which is a critical step in virus infection.Twenty compounds that have been previously reported to inhibit SARS‐CoV‐2 replication were tested by using pseudoviruses containing the spike protein from the original strain(SARS‐CoV‐2‐WH01).The cytotoxicity of these compounds was determined.Furthermore,we identified six compounds with strong antagonistic activity against the WH01 pseudovirus,and low cytotoxicity was identified.These compounds were then evaluated for their efficacy against pseudoviruses expressing the spike protein from B.1.617.2(Delta)and B.1.1.529(Omicron),the two most prevalent circulating strains.These assays demonstrated that two phenothiazine compounds,trifluoperazine 2HCl and thioridazine HCl,inhibit the infection of Delta and Omicron pseudoviruses.Finally,we discovered that these two compounds were highly effective against authentic SARS‐CoV‐2 viruses,including the WH01,Delta,and Omicron strains.Our study identified potential broad‐spectrum SARS‐CoV‐2 inhibitors and provided insights into the development of novel therapeutics.展开更多
基金supported by Young Scientist Fund of National Natural Science Foundation of China(No.51601152)Chunhui Program from Education Ministry of China,Open Research Subject of Key Laboratory of Fluid and Power Machinery of Ministry of Education(No.SZJJ2017-082)the Sichuan Science and Technology Program(No.2019JDTD0024).
文摘Bi_(2)Te_(3) based alloys have been the most widely used thermoelectric material at low temperature for many decades.Here we report Se doped n-type Mg_(3)Bi_(2) based materials with a thermoelectric figure-of-merit ZT of 0.82 at 300 K and a peak ZT of 1.24 at 498 K,which is comparable to the n-type Bi_(2)Te_(3) and Te doped Mg_(3)Bi_(1.4)Sb_(0.6).The improved thermoelectric performance is benefited from the high carrier concentration and mobility as well as the thermal conductivity reduction.The reduced resistivity increased the power factor at all measured temperatures,leading to a higher engineering ZT(ZTeng)and engineering power factor(PFeng)for n-type Mg_(3)Bi_(2).The n-type Mg_(3)Bi_(1.4)Sb_(0.6) materials are promising for thermoelectric power generation and cooling applications near room temperature.
基金supported by the Chunhui Program of the Education Ministry of China,and that at the University of Electronic Science and Technology of China was funded by the Department of Science and Technology of Sichuan Province(2021JDTD0030)the National Natural Science Foundation of China(No.62104032,No.62174022).
文摘Mg_(3)Sb_(1.5)Bi_(0.5)-based Zintl compounds have attracted extensive attention as potential thermoelectric materials due to their earth-abundant elements.However,pure and intrinsic Mg_(3)Sb_(1.5)Bi_(0.5)manifests a poor thermoelectric performance because of its low electrical conductivity of about 3×10^(2)S/m at room temperature.In this work,In and Se co-doping was carried out to optimize the thermoelectric perfor-mance of n-type Mg_(3)Sb_(1.5)Bi_(0.5)-based material.The experimental results revealed that the carrier con-centration and mobility of Mg_(3)Sb_(1.5)Bi_(0.5)significantly increased after In and Se co-doping,leading to an improvement of power factor.Simultaneously,lattice thermal conductivity was significantly reduced due to the large mass difference between In and Mg.A maximum zT of 1.64 at 723 K was obtained for the Mg_(3.17)In_(0.03)Sb_(1.5)Bi_(0.49)Se_(0.01)sample.And an average zT value of about 1.1 between 300 and 723 K was achieved,which insures its possible application at medium temperature range as a non-toxic and low-cost TE material.
基金This study was funded by grants from the National Key Research and Development Program(2021YFC2300603)the National Science Foundation of China(32170157,Key program 81830017,and 81902051),Taishan Scholarship(No.tspd20181201)+1 种基金Major Basic Research Project of Shandong Natural Science Foundation(No.ZR2020ZD12)Collaborative Innovation Center of Technology and Equipment for Biological Diagnosis and Therapy in Universities of Shandong,Key Research and Development Program of Shandong(2019GSF108238).We thank Professor Jincun Zhao(the First Affiliated Hospital of Guangzhou Medical University)for the friendly gifted HCoV-229E virus and S protein expression plasmids of HCoV-NL63 and HCoV-229E.We thank the Translational Medicine Core Facility of Shandong University for the consultation and instrument availability that supported this work.
文摘Dear Editor,To date,seven human coronaviruses(HCoVs)have been identified,among which the highly pathogenic severe acute respiratory syndrome-associated coronavirus(SARS-CoV),Middle East respiratory syndrome coronavirus(MERS-CoV),and severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)have caused public health disasters worldwide.
基金supported by CAMS Innovation Fund for Medical Sciences 2021-I2M-1-038 and 2022-I2M-JB-014(to S.C.)Fundamental Research Funds for the Central Universities 3332021045(to S.G.)+2 种基金National Natural Science Foundation of China 81971950(to J.W.)and 82104250(to J.Z.)We thank the National Microbial Resource Center(No.NMRC-2020-3)the CAMS Collection Center of Pathogenic Microorganisms(CAMS-CCPM-A)for providing valuable reagents.
文摘The coronavirus disease 2019(COVID-19)pandemic has devastated global health.Identifying key host factors essential for SARS-CoV-2 RNA replication is expected to unravel cellular targets for the development of broad-spectrum antiviral drugs which have been quested for the preparedness of future viral outbreaks.Here,we have identified host proteins that associate with nonstructural protein 12(nsp12),the RNA-dependent RNA polymerase(RdRp)of SARS-CoV-2 using a mass spectrometry(MS)-based proteomic approach.Among the candidate factors,CDK2(Cyclin-dependent kinase 2),a member of cyclin-dependent kinases,interacts with nsp12 and causes its phosphorylation at T20,thus facilitating the assembly of the RdRp complex consisting of nsp12,nsp7 and nsp8 and promoting efficient synthesis of viral RNA.The crucial role of CDK2 in viral RdRp function is further supported by our observation that CDK2 inhibitors potently impair viral RNA synthesis and SARS-CoV-2 infection.Taken together,we have discovered CDK2 as a key host factor of SARS-CoV-2 RdRp complex,thus serving a promising target for the development of SARS-CoV-2 RdRp inhibitors.
基金supported by grants from the National Major Sciences&Technology Project for Control and Prevention of Major Infectious Diseases in China(2018ZX10733403 and 2018ZX10101001 to Z.X.,2018ZX10301401 to X.L. and Z.Z.)the National Natural Science Foundation of China(81930063,81971948,81772201,and 31670169 to J.W.,X.L.,Z.X.,and Z.Z.)+1 种基金the National Key R&D Program of China(2020YFA0707600)the Chinese Academy of Medical Sciences(CAMS)Innovation Fund for Medical Sciences(2016-I2M-1-014 to J.W.).
文摘SARS-CoV-2 is the pathogenic agent of COVID-19,which has evolved into a global pandemic.Compared with some other respiratory RNA viruses,SARS-CoV-2 is a poor inducer of type Ⅰ interferon(IFN).Here,we report that SARS-CoV-2 nsp12,the viral RNA-dependent RNA polymerase(RdRp),suppresses host antiviral responses.SARS-CoV-2 nsp12 attenuated Sendai virus(SeV)-or poly(I:C)-induced IFN-β promoter activation in a dose-dependent manner.It also inhibited IFN promoter activation triggered by RIG-I,MDA5,MAVS,and IRF3 overexpression.Nsp12 did not impair IRF3 phosphorylation but suppressed the nuclear translocation of IRF3.Mutational analyses suggested that this suppression was not dependent on the polymerase activity of nsp12.Given these findings,our study reveals that SARS-CoV-2 RdRp can antagonize host antiviral innate immunity and thus provides insights into viral pathogenesis.
基金supported by the CAMS Innovation Fund for Medical Science(CIFMS 2016-I2M-1-014)the National Key Plan for Scientific Research and Development of China(2016YFD0500300)+1 种基金National Key R&D Program of China(2020YFA0707600)Beijing Municipal Science and Technology Project(Z201100001020005)。
文摘Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has caused a devastating pandemic worldwide.Vaccines and antiviral drugs are the most promising candidates for combating this global epidemic,and scientists all over the world have made great efforts to this end.However,manipulation of the SARS-CoV-2 should be performed in the biosafety level3 laboratory.This makes experiments complicated and time-consuming.Therefore,a safer system for working with this virus is urgently needed.Here,we report the construction of plasmid-based,non-infectious SARS-CoV-2 replicons with turbo-green fluorescent protein and/or firefly luciferase reporters by reverse genetics using transformation-associated recombination cloning in Saccharomyces cerevisiae.Replication of these replicons was achieved simply by direct transfection of cells with the replicon plasmids as evident by the expression of reporter genes.Using SARS-CoV-2 replicons,the inhibitory effects of E64-D and remdesivir on SARS-CoV-2 replication were confirmed,and the halfmaximal effective concentration(EC50)value of remdesivir and E64-D was estimated by different quantification methods respectively,indicating that these SARS-CoV-2 replicons are useful tools for antiviral drug evaluation.
基金supported by the National MegaProject for Infectious Disease (2018ZX10301408, China)the National Mega-Project for Significant New Drug Discovery (2018ZX09711003-002-002, China)+3 种基金the National Natural Science Foundation of China (81802019 and 81902075)the Beijing Natural Science Foundation (7184228, China)CAMS Innovation Fund for Medical Sciences (2018-I2M-3-004 and 2020-I2M-2010, China)the Peking Union Medical College Youth Fund (3332016063 and 3332018096, China)。
文摘Severe acute respiratory syndrome coronavirus-2(SARS-CoV-2) has become one major threat to human population health.The RNA-dependent RNA polymerase(RdRp) presents an ideal target of antivirals,whereas nucleoside analogs inhibitor is hindered by the proofreading activity of coronavirus.Herein,we report that corilagin(RAI-S-37) as a non-nucleoside inhibitor of SARS-CoV-2 RdRp,binds directly to RdRp,effectively inhibits the polymerase activity in both cell-free and cell-based assays,fully resists the proofreading activity and potently inhibits SARS-CoV-2 infection with a low 50% effective concentration(EC50) value of 0.13 μmol/L.Computation modeling predicts that RAI-S-37 lands at the palm domain of RdRp and prevents conformational changes required for nucleotide incorporation by RdRp.In addition,combination of RAI-S-37 with remdesivir exhibits additive activity against antiSARS-CoV-2 RdRp.Together with the current data available on the safety and pharmacokinetics of corilagin as a medicinal herbal agent,these results demonstrate the potential of being developed into one of the much-needed SARS-CoV-2 therapeutics.
基金This work was supported by grants from National Key R&D Program of China(2020YFA0707600 to Z.Z.,2020YFA0707800 to W.Wei.)the National Natural Science Foundation of China(81930063,31870893,and 81971948 to J.W.,Z.Z.,and X.L.)+3 种基金the National Major Sciences&Technology Project for Control and Prevention of Major Infectious Diseases in China(2018ZX10301401 to Z.Z.and X.L.)the Beijing Municipal Science&Technology Commission(Z181100001318009)Chinese Academy of Medical Sciences(CAMS)Innovation Fund for Medical Sciences(2016-I2M-1-014,2016-I2M-1-005 to J.W.and X.L.)the Beijing Advanced Innovation Center for Genomics(ICG)at Peking University,and the Peking-Tsinghua Center for Life Sciences.
文摘The global coronavirus disease 2019(COVID-19)pandemic is caused by severe acute respiratory syndrome coronavirus 2(SARSCoV-2),a positive-sense RNA virus.How the host immune system senses and responds to SARS-CoV-2 infection remain largely unresolved.Here,we report that SARS-CoV-2 infection activates the innate immune response through the cytosolic DNA sensing cGAS-STING pathway.SARS-CoV-2 infection induces the cellular level of 2′3′-cGAMP associated with STING activation.cGAS recognizes chromatin DNA shuttled from the nucleus as a result of cell-to-cell fusion upon SARS-CoV-2 infection.We further demonstrate that the expression of spike protein from SARS-CoV-2 and ACE2 from host cells is sufficient to trigger cytoplasmic chromatin upon cell fusion.Furthermore,cytoplasmic chromatin-cGAS-STING pathway,but not MAVS-mediated viral RNA sensing pathway,contributes to interferon and pro-inflammatory gene expression upon cell fusion.Finally,we show that cGAS is required for host antiviral responses against SARS-CoV-2,and a STING-activating compound potently inhibits viral replication.Together,our study reported a previously unappreciated mechanism by which the host innate immune system responds to SARS-CoV-2 infection,mediated by cytoplasmic chromatin from the infected cells.Targeting the cytoplasmic chromatin-cGAS-STING pathway may offer novel therapeutic opportunities in treating COVID-19.In addition,these findings extend our knowledge in host defense against viral infection by showing that host cells’self-nucleic acids can be employed as a“danger signal”to alarm the immune system.
基金supported by grants from National Key R&D Program of China(2020YFA0707600 to Z.Z.and X.L.)the National Natural Science Foundation of China(81930063 and 81971948 to J.W.and X.L.)hinese Academy of Medical Science(CAMS)Innovation Fund for Medical Sciences(2021-I2M-1-038 to J.W.)。
文摘Severe acute respiratory syndrome coronavirus 2(SARS‐CoV‐2)continues to evolve,generating new variants that pose a threat to global health;therefore,it is imperative to obtain safe and broad‐spectrum antivirals against SARS‐CoV‐2 and its variants.To this end,we screened compounds for their ability to inhibit viral entry,which is a critical step in virus infection.Twenty compounds that have been previously reported to inhibit SARS‐CoV‐2 replication were tested by using pseudoviruses containing the spike protein from the original strain(SARS‐CoV‐2‐WH01).The cytotoxicity of these compounds was determined.Furthermore,we identified six compounds with strong antagonistic activity against the WH01 pseudovirus,and low cytotoxicity was identified.These compounds were then evaluated for their efficacy against pseudoviruses expressing the spike protein from B.1.617.2(Delta)and B.1.1.529(Omicron),the two most prevalent circulating strains.These assays demonstrated that two phenothiazine compounds,trifluoperazine 2HCl and thioridazine HCl,inhibit the infection of Delta and Omicron pseudoviruses.Finally,we discovered that these two compounds were highly effective against authentic SARS‐CoV‐2 viruses,including the WH01,Delta,and Omicron strains.Our study identified potential broad‐spectrum SARS‐CoV‐2 inhibitors and provided insights into the development of novel therapeutics.