针对美军移动用户目标系统(mobile user objective system,MUOS)卫星通信无线信道传输特性分析问题,运用统计模型分析策略对其进行研究。在分析美军MUOS系统(移动用户目标系统)的UHF频段(ultra high frequency band)和Ka频段(K-above ba...针对美军移动用户目标系统(mobile user objective system,MUOS)卫星通信无线信道传输特性分析问题,运用统计模型分析策略对其进行研究。在分析美军MUOS系统(移动用户目标系统)的UHF频段(ultra high frequency band)和Ka频段(K-above band)2种通信链无线信道传播损耗、多径衰落特性等的基础上,研究MUOS系统2种通信链路无线信道传播特性。分析结果表明:UHF频段无线信道具有复杂的时变衰落特性,其传播特性受移动终端所处的物理环境、场景影响较大;Ka波段与UHF频段相比干扰较小,其传播特性主要受到大气效应的影响,其中雨衰影响最为显著。该研究可为后续开展该系统链路干扰技术研究提供参考。展开更多
The global outbreak of coronavirus disease 19(COVID-19),caused by severe acute respiratory syndrome coronavirus 2(SARS-Co V-2),has raised significant global apprehension.Developing a rapid,efficient,sensitive,and accu...The global outbreak of coronavirus disease 19(COVID-19),caused by severe acute respiratory syndrome coronavirus 2(SARS-Co V-2),has raised significant global apprehension.Developing a rapid,efficient,sensitive,and accurate point-of-care detection method is imperative for curbing SARS-Co V-2 transmission.Here,we screened a sequence,designed a set of highly sensitive loopmediated isothermal amplification primers(LAMP)and g RNA,and developed a user-friendly detection platform combining CRISPRCas12a and RT-LAMP technology to specifically detect SARS-Co V-2 and its 5 variants.Bioinformatics analysis and Cas12a-g RNA identification ensured sequence specificity,allowing us to identify SARS-Co V-2 mutations.We developed a method for the detection of SARSCoV-2 using these primers in combination with LAMP amplification and CRISPR-Cas12a technology.This method is designed to detect SARS-CoV-2(NC_045512),Alpha(B.1.1.7),Beta(B.1.351),Gamma(P.1),Delta(B.1.617.2)and Omicron(B.1.1.529).Additionally,it can differentiate SARS-CoV-2 from other coronaviruses.Quantitative analysis can be conducted by measuring fluorescence values,while qualitative analysis can be performed by observing fluorescence color point-of-care diagnosis changes with the naked eye.These results suggest that a set of novel sensitive LAMP primers and g RNA have been obtained to detect the extensive variants,and the RT-LAMPCRISPR-Cas12a platform significantly facilitates point-of-care diagnosis,thereby halting the spread of SARS-Co V-2,thus contributing to COVID-19 prevention and control.展开更多
To design a releasable PEGylated TNF-α(rPEG-TNF-α ), a cathepsin B-sensitive dipeptide (Val-Cit moiety) was inserted into conventional PEG-modified TNF- (PEG-TNF- ), facilitating its clinical use for anti-tumor ther...To design a releasable PEGylated TNF-α(rPEG-TNF-α ), a cathepsin B-sensitive dipeptide (Val-Cit moiety) was inserted into conventional PEG-modified TNF- (PEG-TNF- ), facilitating its clinical use for anti-tumor therapy. Comparative pharmaco- kinetic and pharmacodynamic studies showed that the half-lives of both PEGylated forms of TNF-α were ~60-fold greater than that of unmodified TNF-α . In addition, the in vitro bioactivity of rPEG-TNF-α was greater than that of PEG-TNF-α with the same degree of PEG modification. Release of TNF-α from rPEG-TNF-α in vitro was dependent on the presence of cathepsin B and was inhibited by a cathepsin B inhibitor. Despite the potent cytotoxicity of unmodified TNF-α against normal cells, its PEGylated forms at higher TNF-α concentrations showed low cytotoxic activity against these cells. In contrast, both forms of PEGylated TNF-α showed potent cytotoxic activity against the B16 and L929 cell lines, with rPEG-TNF-α being 5- and 9- fold more potent, respectively, than PEG-TNF-α . Moreover, rPEG-TNF-α was a more potent in vivo antitumor agent than PEG-TNF-α .展开更多
文摘针对美军移动用户目标系统(mobile user objective system,MUOS)卫星通信无线信道传输特性分析问题,运用统计模型分析策略对其进行研究。在分析美军MUOS系统(移动用户目标系统)的UHF频段(ultra high frequency band)和Ka频段(K-above band)2种通信链无线信道传播损耗、多径衰落特性等的基础上,研究MUOS系统2种通信链路无线信道传播特性。分析结果表明:UHF频段无线信道具有复杂的时变衰落特性,其传播特性受移动终端所处的物理环境、场景影响较大;Ka波段与UHF频段相比干扰较小,其传播特性主要受到大气效应的影响,其中雨衰影响最为显著。该研究可为后续开展该系统链路干扰技术研究提供参考。
基金Supported by the National Natural Sciences Foundation of China(52073022)the Fundamental Research Funds for the Central Universities of China and the Translational Medical Research Fund of Wuhan University Taikang Medical School(School of Basic Medical Sciences)the Key Laboratory of Environmental Pollution Monitoring and Disease Control(Guizhou Medical University)Ministry of Education(GMU-2022-HJZ)。
文摘The global outbreak of coronavirus disease 19(COVID-19),caused by severe acute respiratory syndrome coronavirus 2(SARS-Co V-2),has raised significant global apprehension.Developing a rapid,efficient,sensitive,and accurate point-of-care detection method is imperative for curbing SARS-Co V-2 transmission.Here,we screened a sequence,designed a set of highly sensitive loopmediated isothermal amplification primers(LAMP)and g RNA,and developed a user-friendly detection platform combining CRISPRCas12a and RT-LAMP technology to specifically detect SARS-Co V-2 and its 5 variants.Bioinformatics analysis and Cas12a-g RNA identification ensured sequence specificity,allowing us to identify SARS-Co V-2 mutations.We developed a method for the detection of SARSCoV-2 using these primers in combination with LAMP amplification and CRISPR-Cas12a technology.This method is designed to detect SARS-CoV-2(NC_045512),Alpha(B.1.1.7),Beta(B.1.351),Gamma(P.1),Delta(B.1.617.2)and Omicron(B.1.1.529).Additionally,it can differentiate SARS-CoV-2 from other coronaviruses.Quantitative analysis can be conducted by measuring fluorescence values,while qualitative analysis can be performed by observing fluorescence color point-of-care diagnosis changes with the naked eye.These results suggest that a set of novel sensitive LAMP primers and g RNA have been obtained to detect the extensive variants,and the RT-LAMPCRISPR-Cas12a platform significantly facilitates point-of-care diagnosis,thereby halting the spread of SARS-Co V-2,thus contributing to COVID-19 prevention and control.
基金supported by the National Natural Science Foundation of China (30701055)in part by the China Postdoctoral Science Foundation(20070410029)in part by the Foundation of Innovation Team at the Chongqing University of Science and Technology (2007)
文摘To design a releasable PEGylated TNF-α(rPEG-TNF-α ), a cathepsin B-sensitive dipeptide (Val-Cit moiety) was inserted into conventional PEG-modified TNF- (PEG-TNF- ), facilitating its clinical use for anti-tumor therapy. Comparative pharmaco- kinetic and pharmacodynamic studies showed that the half-lives of both PEGylated forms of TNF-α were ~60-fold greater than that of unmodified TNF-α . In addition, the in vitro bioactivity of rPEG-TNF-α was greater than that of PEG-TNF-α with the same degree of PEG modification. Release of TNF-α from rPEG-TNF-α in vitro was dependent on the presence of cathepsin B and was inhibited by a cathepsin B inhibitor. Despite the potent cytotoxicity of unmodified TNF-α against normal cells, its PEGylated forms at higher TNF-α concentrations showed low cytotoxic activity against these cells. In contrast, both forms of PEGylated TNF-α showed potent cytotoxic activity against the B16 and L929 cell lines, with rPEG-TNF-α being 5- and 9- fold more potent, respectively, than PEG-TNF-α . Moreover, rPEG-TNF-α was a more potent in vivo antitumor agent than PEG-TNF-α .
