Wideband acoustic imaging,which combines compressed sensing(CS)and microphone arrays,is widely used for locating acoustic sources.However,the location results of this method are unstable,and the computational efficien...Wideband acoustic imaging,which combines compressed sensing(CS)and microphone arrays,is widely used for locating acoustic sources.However,the location results of this method are unstable,and the computational efficiency is low.In this work,in order to improve the robustness and reduce the computational cost,a DCS-SOMP-SVD compressed sensing method,which combines the distributed compressed sensing using simultaneously orthogonal matching pursuit(DCS-SOMP)and singular value decomposition(SVD)is proposed.The performance of the DCS-SOMP-SVD is studied through both simulation and experiment.In the simulation,the locating results of the DCS-SOMP-SVD method are compared with the wideband BP method and the DCS-SOMP method.In terms of computational efficiency,the proposed method is as efficient as the DCS-SOMP method and more efficient than the wideband BP method.In terms of locating accuracy,the proposed method can still locate all sources when the signal to noise ratio(SNR)is−20 dB,while the wideband BP method and the DCS-SOMP method can only locate all sources when the SNR is higher than 0 dB.The performance of the proposed method can be improved by expanding the frequency range.Moreover,there is no extra source in the maps of the proposed method,even though the target sparsity is overestimated.Finally,a gas leak experiment is conducted to verify the feasibility of the DCS-SOMP-SVD method in the practical engineering environment.The experimental results show that the proposed method can locate both two leak sources in different frequency ranges.This research proposes a DCS-SOMP-SVD method which has sufficient robustness and low computational cost for wideband acoustic imaging.展开更多
Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)is continuously evolving since 2019.Some monoclonal antibodies(mAbs)have been developed and widely used,such as etesevimab(CB6)developed by Eli-Lilly/Junshi.H...Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)is continuously evolving since 2019.Some monoclonal antibodies(mAbs)have been developed and widely used,such as etesevimab(CB6)developed by Eli-Lilly/Junshi.However,the mAb escaped from the variant of concern(VOC)ever since the emergence of Beta VOC,with a complete loss of efficacy against the Omicron subvariants.Here,we developed a broad-spectrum and affinity-mature antibody design(BAADesign)procedure to design CB6,enabling it to bind to the receptor-binding domains(RBDs)of multiple important Omicron subvariants,including the recent variant KP.2.Structural analysis confirmed the desired CB6-RBD interactions.Additionally,identical mutations in the complementarity determining regions(CDR)1 and CDR2 of the CB6 mutants also restored neutralizing potency for some RBD-1 group antibodies.Overall,the enhanced CB6 neutralizing capacity makes it a promising candidate against SARS-CoV-2 infection,and the BAADesign method has implications for the design of other antibodies.展开更多
Coronaviruses(CoVs)pose a continual threat to global public health due to their broad host range and potential for cross-species transmission.Notable examples include the severe acute respiratory syndrome coronavirus(...Coronaviruses(CoVs)pose a continual threat to global public health due to their broad host range and potential for cross-species transmission.Notable examples include the severe acute respiratory syndrome coronavirus(SARS-CoV)in 2002 andMiddle East respiratory syndrome coronavirus(MERS-CoV)in 2012,each causing worldwide health emergencies.Despite vaccine and antiviral development targeting theseCoVs,newCoVs regularly emerge in animals,often without attracting significant attention.展开更多
Dear Editor,The coronavirus disease 2019(COVID-19)pandemic,caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),is a great threat to global public health.Although several vaccines and therapeutic anti...Dear Editor,The coronavirus disease 2019(COVID-19)pandemic,caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),is a great threat to global public health.Although several vaccines and therapeutic antibodies have been authorized for emergency use,several studies have reported that they show weakened protective effects against SARS-CoV-2 variants,including Alpha,Beta,Gamma,and currently dominant Delta and Lambda.展开更多
While human induced pluripotent stem cells(hiPSCs)have promising applications in regenerative medicine,most of the hiPSC lines available today are not suitable for clinical applications due to contamination with nonhu...While human induced pluripotent stem cells(hiPSCs)have promising applications in regenerative medicine,most of the hiPSC lines available today are not suitable for clinical applications due to contamination with nonhuman materials,such as sialic acid,and potential pathogens from animal-product-containing cell culture systems.Although several xeno-free cell culture systems have been established recently,their use of human fibroblasts as feeders reduces the clinical potential of hiPSCs due to batch-to-batch variation in the feeders and time-consuming preparation processes.In this study,we have developed a xeno-free and feeder-cell-free human embryonic stem cell(hESC)/hiPSC culture system using human plasma and human placenta extracts.The system maintains the self-renewing capacity and pluripotency of hESCs for more than 40 passages.Human iPSCs were also derived from human dermal fibroblasts using this culture system by overexpressing three transcription factors—Oct4,Sox2 and Nanog.The culture system developed here is inexpensive and suitable for large scale production.展开更多
基金Supported by National Natural Science Foundation of China(Grant Nos.51675425,52075441)Shaanxi Provincial Key Research Program Project of China(Grant No.2020ZDLGY06-09)+1 种基金Dongguan Municipal Social Science and Technology Development(key)Project of China(Grant No.20185071021600)Science and Technology on Micro-system Laboratory Foundation of China(Grant No.6142804200405).
文摘Wideband acoustic imaging,which combines compressed sensing(CS)and microphone arrays,is widely used for locating acoustic sources.However,the location results of this method are unstable,and the computational efficiency is low.In this work,in order to improve the robustness and reduce the computational cost,a DCS-SOMP-SVD compressed sensing method,which combines the distributed compressed sensing using simultaneously orthogonal matching pursuit(DCS-SOMP)and singular value decomposition(SVD)is proposed.The performance of the DCS-SOMP-SVD is studied through both simulation and experiment.In the simulation,the locating results of the DCS-SOMP-SVD method are compared with the wideband BP method and the DCS-SOMP method.In terms of computational efficiency,the proposed method is as efficient as the DCS-SOMP method and more efficient than the wideband BP method.In terms of locating accuracy,the proposed method can still locate all sources when the signal to noise ratio(SNR)is−20 dB,while the wideband BP method and the DCS-SOMP method can only locate all sources when the SNR is higher than 0 dB.The performance of the proposed method can be improved by expanding the frequency range.Moreover,there is no extra source in the maps of the proposed method,even though the target sparsity is overestimated.Finally,a gas leak experiment is conducted to verify the feasibility of the DCS-SOMP-SVD method in the practical engineering environment.The experimental results show that the proposed method can locate both two leak sources in different frequency ranges.This research proposes a DCS-SOMP-SVD method which has sufficient robustness and low computational cost for wideband acoustic imaging.
基金supported by the National Natural Science Foundation of China(82225021)the National Key R&D Program of China(2022YFC2303403,2021YFA1300803,2021YFA1301404).
文摘Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)is continuously evolving since 2019.Some monoclonal antibodies(mAbs)have been developed and widely used,such as etesevimab(CB6)developed by Eli-Lilly/Junshi.However,the mAb escaped from the variant of concern(VOC)ever since the emergence of Beta VOC,with a complete loss of efficacy against the Omicron subvariants.Here,we developed a broad-spectrum and affinity-mature antibody design(BAADesign)procedure to design CB6,enabling it to bind to the receptor-binding domains(RBDs)of multiple important Omicron subvariants,including the recent variant KP.2.Structural analysis confirmed the desired CB6-RBD interactions.Additionally,identical mutations in the complementarity determining regions(CDR)1 and CDR2 of the CB6 mutants also restored neutralizing potency for some RBD-1 group antibodies.Overall,the enhanced CB6 neutralizing capacity makes it a promising candidate against SARS-CoV-2 infection,and the BAADesign method has implications for the design of other antibodies.
基金supported by the National Natural Science Foun-dation of China(grant number 32222006 to P.H.)。
文摘Coronaviruses(CoVs)pose a continual threat to global public health due to their broad host range and potential for cross-species transmission.Notable examples include the severe acute respiratory syndrome coronavirus(SARS-CoV)in 2002 andMiddle East respiratory syndrome coronavirus(MERS-CoV)in 2012,each causing worldwide health emergencies.Despite vaccine and antiviral development targeting theseCoVs,newCoVs regularly emerge in animals,often without attracting significant attention.
基金This work was supported by the Ministry of Science and Technology of the People’s Republic of China(2021YFC0863300)the National Key Research and Development Program of China(2020YFA0509202)the Strategic Priority Research Program of CAS(XDB29040203).
文摘Dear Editor,The coronavirus disease 2019(COVID-19)pandemic,caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),is a great threat to global public health.Although several vaccines and therapeutic antibodies have been authorized for emergency use,several studies have reported that they show weakened protective effects against SARS-CoV-2 variants,including Alpha,Beta,Gamma,and currently dominant Delta and Lambda.
基金by the National High Technology Research and Development Program(863 ProgramGrant No.2006AA02A106)+3 种基金the National Basic Research Program(973 ProgramGrant Nos.2006CB943901,2010CB945024,and 2011CB965002)the Knowledge Innovation Program of the Chinese Academy of Sciences(KSCX2-YW-R-50)the National Foundation of Science and Technology(No.30640005).
文摘While human induced pluripotent stem cells(hiPSCs)have promising applications in regenerative medicine,most of the hiPSC lines available today are not suitable for clinical applications due to contamination with nonhuman materials,such as sialic acid,and potential pathogens from animal-product-containing cell culture systems.Although several xeno-free cell culture systems have been established recently,their use of human fibroblasts as feeders reduces the clinical potential of hiPSCs due to batch-to-batch variation in the feeders and time-consuming preparation processes.In this study,we have developed a xeno-free and feeder-cell-free human embryonic stem cell(hESC)/hiPSC culture system using human plasma and human placenta extracts.The system maintains the self-renewing capacity and pluripotency of hESCs for more than 40 passages.Human iPSCs were also derived from human dermal fibroblasts using this culture system by overexpressing three transcription factors—Oct4,Sox2 and Nanog.The culture system developed here is inexpensive and suitable for large scale production.
