Dear Editor,Since 2024,the clade 2.3.4.4b highly pathogenic avian influenza(HPAI)H5N1 viruses have been identified in dairy cattle in the United States,raising global concerns about public health(Neumann and Kawaoka,2...Dear Editor,Since 2024,the clade 2.3.4.4b highly pathogenic avian influenza(HPAI)H5N1 viruses have been identified in dairy cattle in the United States,raising global concerns about public health(Neumann and Kawaoka,2024).As of December 18,2024,the U.S.Centers for Disease Control and Prevention(CDC)has reported over 61 confirmed cases of H5N1 infection in humans,predominantly associated with exposure to infected poultry or dairy cattle(U.S.Centers for Disease Control and Prevention,2024).Notably,the circulating 2.3.4.4b H5N1 clade has demonstrated continuous evolution in both wild and domestic birds globally,with expanding mammalian host tropism that now includes swine,cats,red foxes,harbor seals,and skunks(Peacock et al.,2024).These viruses have not only incurred substantial economic impacts but also posed dual threats to human health and ecological stability particularly during co-infections with other viruses(Abolnik,2024;Wang and Wang,2023).展开更多
Highly pathogenic avian influenza(HPAI)H5 viruses have caused widespread mortality in wild birds and poultry,with increasing spillover risk into mammals.The recently dominant clade 2.3.4.4b has produced multiple epide...Highly pathogenic avian influenza(HPAI)H5 viruses have caused widespread mortality in wild birds and poultry,with increasing spillover risk into mammals.The recently dominant clade 2.3.4.4b has produced multiple epidemic waves,first driven by H5N8 and more recently by H5N1,which has spread more rapidly,infected a broader host range,and caused higher mortality.While earlier studies identified consistent roles of waterbird community composition in shaping HPAI outbreaks,it remains unclear whether these factors also apply to the currently circulating H5N1.We analyzed HPAI H5N1 outbreaks in European wild birds during the 2021/22epidemic,examining the influence of waterbird communities and environmental variables,and compared these patterns with earlier epidemics,including H5N1 in 2005/06 and H5N8 in 2016/17 and 2020/21.Our results showed that waterbird abundance,species richness,and the abundance of key species were positively associated with disease occurrence,whereas phylogenetic diversity was negatively associated,suggesting greater interspecific transmission among closely related hosts.Models trained on earlier epidemics accurately predicted the H5N1 occurrence in 2021/22.These findings demonstrate consistent effects of waterbird community composition across multiple epidemics and highlight their values as predictors of HPAI risk.Integrating community metrics into surveillance and early-warning systems can strengthen our capacity to anticipate future outbreaks across clades and subtypes.展开更多
为了提高金刚石-铜合金复合材料的界面粘结强度,本文用差热分析(DTA)、X 射线衍射分析、SEM 观察及磨削试验研究了金刚石表面的 Ti 镀层对金刚石-铜基合金复合材料界面结构及性能的影响。结果表明,在600～1200℃镀Ti 层与金刚石发生界...为了提高金刚石-铜合金复合材料的界面粘结强度,本文用差热分析(DTA)、X 射线衍射分析、SEM 观察及磨削试验研究了金刚石表面的 Ti 镀层对金刚石-铜基合金复合材料界面结构及性能的影响。结果表明,在600～1200℃镀Ti 层与金刚石发生界面反应,在金刚石表面外延生成岛状 TiC,从而实现了金刚石与铜基合金的冶金结合。镀 Ti 金刚石与铜合金的粘结强度可达8×10~7Pa。用镀 Ti金刚石制成的铜基合金磨块对花岗岩的磨削比与不镀钛金刚石相比提高30%。展开更多
文摘Dear Editor,Since 2024,the clade 2.3.4.4b highly pathogenic avian influenza(HPAI)H5N1 viruses have been identified in dairy cattle in the United States,raising global concerns about public health(Neumann and Kawaoka,2024).As of December 18,2024,the U.S.Centers for Disease Control and Prevention(CDC)has reported over 61 confirmed cases of H5N1 infection in humans,predominantly associated with exposure to infected poultry or dairy cattle(U.S.Centers for Disease Control and Prevention,2024).Notably,the circulating 2.3.4.4b H5N1 clade has demonstrated continuous evolution in both wild and domestic birds globally,with expanding mammalian host tropism that now includes swine,cats,red foxes,harbor seals,and skunks(Peacock et al.,2024).These viruses have not only incurred substantial economic impacts but also posed dual threats to human health and ecological stability particularly during co-infections with other viruses(Abolnik,2024;Wang and Wang,2023).
基金supported by the National Natural Science Foundation of China(32271605)。
文摘Highly pathogenic avian influenza(HPAI)H5 viruses have caused widespread mortality in wild birds and poultry,with increasing spillover risk into mammals.The recently dominant clade 2.3.4.4b has produced multiple epidemic waves,first driven by H5N8 and more recently by H5N1,which has spread more rapidly,infected a broader host range,and caused higher mortality.While earlier studies identified consistent roles of waterbird community composition in shaping HPAI outbreaks,it remains unclear whether these factors also apply to the currently circulating H5N1.We analyzed HPAI H5N1 outbreaks in European wild birds during the 2021/22epidemic,examining the influence of waterbird communities and environmental variables,and compared these patterns with earlier epidemics,including H5N1 in 2005/06 and H5N8 in 2016/17 and 2020/21.Our results showed that waterbird abundance,species richness,and the abundance of key species were positively associated with disease occurrence,whereas phylogenetic diversity was negatively associated,suggesting greater interspecific transmission among closely related hosts.Models trained on earlier epidemics accurately predicted the H5N1 occurrence in 2021/22.These findings demonstrate consistent effects of waterbird community composition across multiple epidemics and highlight their values as predictors of HPAI risk.Integrating community metrics into surveillance and early-warning systems can strengthen our capacity to anticipate future outbreaks across clades and subtypes.
文摘为了提高金刚石-铜合金复合材料的界面粘结强度,本文用差热分析(DTA)、X 射线衍射分析、SEM 观察及磨削试验研究了金刚石表面的 Ti 镀层对金刚石-铜基合金复合材料界面结构及性能的影响。结果表明,在600～1200℃镀Ti 层与金刚石发生界面反应,在金刚石表面外延生成岛状 TiC,从而实现了金刚石与铜基合金的冶金结合。镀 Ti 金刚石与铜合金的粘结强度可达8×10~7Pa。用镀 Ti金刚石制成的铜基合金磨块对花岗岩的磨削比与不镀钛金刚石相比提高30%。
