Staphylococcus aureus is a serious foodborne pathogen threatening food safety and public health.Especially the emergence of methicillin-resistant Staphylococcus aureus(MRSA)increased the difficulty of S.aureus treatme...Staphylococcus aureus is a serious foodborne pathogen threatening food safety and public health.Especially the emergence of methicillin-resistant Staphylococcus aureus(MRSA)increased the difficulty of S.aureus treatment.Staphyloxanthin is a crucial virulence factor of S.aureus.Blocking staphyloxanthin production could help the host immune system counteract the invading S.aureus cells.In this study,we first screened for staphyloxanthin inhibitors using a virtual screening method.The outcome of the virtual screening method resulted in the identification of eugenol(300μg/mL),which significantly inhibits the staphyloxanthin production in S.aureus ATCC 29213,S.aureus Newman,MRSA ATCC 43300 and MRSA ATCC BAA1717by 84.2%,63.5%,68.1%,and 79.5%,respectively.The outcome of the growth curve assay,field-emission scanning electron,and confocal laser scanning microscopy analyses confirmed that eugenol at the test concentration did not affect the morphology and growth of S.aureus.Moreover,the survival rate of S.aureus ATCC 29213 and MRSA ATCC 43300 under H_(2)O_(2) pressure decreased to 51.9%and 45.5%in the presence of eugenol,respectively.The quantitative RT-PCR and molecular simulation studies revealed that eugenol targets staphyloxanthin biosynthesis by downregulating the transcription of the crtM gene and inhibiting the activity of the CrtM enzyme.Taken together,we first determined that eugenol was a prominent compound for staphyloxanthin inhibitor to combat S.aureus especially MRSA infections.展开更多
云污染会严重影响云区辐射的模拟,导致大量云区卫星资料被废弃。结合快速辐射传输模式(Community Radiative Transfer Model,CRTM)的应用现状以及红外遥感原理,对CRTM模式中的辐射传输模块进行了修改,并提出了能够模拟云区红外辐射的CRT...云污染会严重影响云区辐射的模拟,导致大量云区卫星资料被废弃。结合快速辐射传输模式(Community Radiative Transfer Model,CRTM)的应用现状以及红外遥感原理,对CRTM模式中的辐射传输模块进行了修改,并提出了能够模拟云区红外辐射的CRTM云模式。利用CRTM云模式模拟了高光谱大气红外探测器(Atmospheric Infrared Sounder,AIRS)的通道亮温,并针对云模式中新增的参数进行了敏感性分析。结果表明,随着通道高度的下移,对卫星接收辐射贡献较大的大气层也在下移,偏差大值区所处的高度也越来越低;在偏差大值区中,偏差值会随着云量的增加而增大,直到全云覆盖时,偏差值最大;云量较大时,输入的温度廓线的垂直变化会引起云顶发射辐射产生相同的垂直分布,这与用CRTM云模式模拟出的亮温随云顶高度抬升而出现的垂直变化一致;用CRTM云模式模拟的亮温值对新增的云量和云顶高度参数的敏感性较强,符合大气红外辐射传输的规律。展开更多
首次将MSG-2(Meteosat Second Generation-2)卫星上的旋转增强可见光及红外成像仪(Spinning Enhanced Visible and Infrared Imager,SEVIRI)的观测资料同化到美国国家环境预报中心(National Centers for Environmental Prediction,NCEP...首次将MSG-2(Meteosat Second Generation-2)卫星上的旋转增强可见光及红外成像仪(Spinning Enhanced Visible and Infrared Imager,SEVIRI)的观测资料同化到美国国家环境预报中心(National Centers for Environmental Prediction,NCEP)全球资料同化系统(global data assimilation system,GDAS)中。对当前的地球静止业务环境卫星(Geostationary Operational Environmental Satellite,GOES)成像仪资料的同化问题也进行了进一步探讨。利用CRTM(The Community Radiative Transfer Model)模式,对SEVIRI辐射率观测资料进行了模拟。为了对红外辐射率资料进行模拟,CRTM模式中的几个关键部分得到改进,例如:动态更新地面发射率资料以及采用了快速精确的气体吸收模块。为了改进对SEVIRI和GOES成像仪辐射率资料的模拟效果,采用了GSICS(The Global Space-Based Inter-Calibration System)标定订正。初步研究结果表明,包含对SEVIRI辐射率资料的水汽通道(6.25和7.35μm)和二氧化碳通道(13.40μm)的同化对GFS(Global Forecast System)6d预报具有显著的正影响;而对其他5个SEVIRI红外窗口通道资料的同化则减小了这种正影响。通过应用GSICS标定算法,订正了SEVIRI和GOES-12成像仪观测资料的偏差,提高了对GFS预报的影响。此外,还需作进一步研究来提高对SEVIRI红外窗口通道辐射率资料同化的有效性。展开更多
基金supported by the National Natural Science Foundation of China (31972169 and 32001798)。
文摘Staphylococcus aureus is a serious foodborne pathogen threatening food safety and public health.Especially the emergence of methicillin-resistant Staphylococcus aureus(MRSA)increased the difficulty of S.aureus treatment.Staphyloxanthin is a crucial virulence factor of S.aureus.Blocking staphyloxanthin production could help the host immune system counteract the invading S.aureus cells.In this study,we first screened for staphyloxanthin inhibitors using a virtual screening method.The outcome of the virtual screening method resulted in the identification of eugenol(300μg/mL),which significantly inhibits the staphyloxanthin production in S.aureus ATCC 29213,S.aureus Newman,MRSA ATCC 43300 and MRSA ATCC BAA1717by 84.2%,63.5%,68.1%,and 79.5%,respectively.The outcome of the growth curve assay,field-emission scanning electron,and confocal laser scanning microscopy analyses confirmed that eugenol at the test concentration did not affect the morphology and growth of S.aureus.Moreover,the survival rate of S.aureus ATCC 29213 and MRSA ATCC 43300 under H_(2)O_(2) pressure decreased to 51.9%and 45.5%in the presence of eugenol,respectively.The quantitative RT-PCR and molecular simulation studies revealed that eugenol targets staphyloxanthin biosynthesis by downregulating the transcription of the crtM gene and inhibiting the activity of the CrtM enzyme.Taken together,we first determined that eugenol was a prominent compound for staphyloxanthin inhibitor to combat S.aureus especially MRSA infections.
基金美国NOAA和NASA GOES-R Algorithm Working Group和GOES-R Risk Reduction关于地球静止卫星资料模拟和同化项目
文摘首次将MSG-2(Meteosat Second Generation-2)卫星上的旋转增强可见光及红外成像仪(Spinning Enhanced Visible and Infrared Imager,SEVIRI)的观测资料同化到美国国家环境预报中心(National Centers for Environmental Prediction,NCEP)全球资料同化系统(global data assimilation system,GDAS)中。对当前的地球静止业务环境卫星(Geostationary Operational Environmental Satellite,GOES)成像仪资料的同化问题也进行了进一步探讨。利用CRTM(The Community Radiative Transfer Model)模式,对SEVIRI辐射率观测资料进行了模拟。为了对红外辐射率资料进行模拟,CRTM模式中的几个关键部分得到改进,例如:动态更新地面发射率资料以及采用了快速精确的气体吸收模块。为了改进对SEVIRI和GOES成像仪辐射率资料的模拟效果,采用了GSICS(The Global Space-Based Inter-Calibration System)标定订正。初步研究结果表明,包含对SEVIRI辐射率资料的水汽通道(6.25和7.35μm)和二氧化碳通道(13.40μm)的同化对GFS(Global Forecast System)6d预报具有显著的正影响;而对其他5个SEVIRI红外窗口通道资料的同化则减小了这种正影响。通过应用GSICS标定算法,订正了SEVIRI和GOES-12成像仪观测资料的偏差,提高了对GFS预报的影响。此外,还需作进一步研究来提高对SEVIRI红外窗口通道辐射率资料同化的有效性。
