The recent concurrent emergence of H5N1,H5N6,and H5N8 avian influenza viruses(AIVs)has led to significant avian mortality globally.Since 2020,frequent human-animal interactions have been documented.To gain insight int...The recent concurrent emergence of H5N1,H5N6,and H5N8 avian influenza viruses(AIVs)has led to significant avian mortality globally.Since 2020,frequent human-animal interactions have been documented.To gain insight into the novel H5 subtype AIVs(i.e.,H5N1,H5N6 and H5N8),we collected 6102 samples from various regions of China between January 2021 and September 2022,and identified 41 H5Nx strains.Comparative analyses on the evolution and biological properties of these isolates were conducted.Phylogenetic analysis revealed that the 41 H5Nx strains belonged to clade 2.3.4.4b,with 13 related to H5N1,19 to H5N6,and 9 to H5N8.Analysis based on global 2.3.4.4b viruses showed that all the viruses described in this study were likely originated from H5N8,exhibiting a heterogeneous evolutionary history between H5N1 and H5N6 during 2015–2022 worldwide.H5N1 showed a higher rate of evolution in 2021–2022 and more sites under positive selection pressure in 2015–2022.The antigenic profiles of the novel H5N1 and H5N6 exhibited notable variations.Further hemagglutination inhibition assay suggested that some A(H5N1)viruses may be antigenically distinct from the circulating H5N6 and H5N8 strains.Mammalian challenge assays demonstrated that the H5N8 virus(21GD001_H5N8)displayed the highest pathogenicity in mice,followed by the H5N1 virus(B1557_H5N1)and then the H5N6 virus(220086_H5N6),suggesting a heterogeneous virulence profile of H5 AIVs in the mammalian hosts.Based on the above results,we speculate that A(H5N1)viruses have a higher risk of emergence in the future.Collectively,these findings unveil a new landscape of different evolutionary history and biological characteristics of novel H5 AIVs in clade 2.3.4.4b,contributing to a better understanding of designing more effective strategies for the prevention and control of novel H5 AIVs.展开更多
A sampling campaign including summer, autumn and winter of 2014 and spring of 2015 was accomplished to obtain the characteristic of chemical components in PM2.5 at three sites ofKunming, a plateau city in South-west C...A sampling campaign including summer, autumn and winter of 2014 and spring of 2015 was accomplished to obtain the characteristic of chemical components in PM2.5 at three sites ofKunming, a plateau city in South-west China. Nine kinds of water-soluble inorganic ions （WSI）, organic and element carbon （OC and EC） in PM2.5 were analyzed by ion chromatography and thermal optical reflectance method, respectively. Results showed that the average concentrations of total WSI, OC and EC were 22.85±10.95 μg.m -3, 17.83±9.57 μg.m-3 and 5.114-4.29 μg.m-3, respectively. They totally accounted for 53.0% of PM2.5. Secondary organic and inorganic aerosols （SOA and SIA） were also assessed by the minimum ratio of OC/EC, nitrogen and sulfur oxidation ratios. The annual average concentrations of SOA and SIA totally accounted for 28.3% of the PM2.5 concentration. The low proportion suggested the primary emission was the main source of PM2.5 in Kunming. However, secondary pollution in the plateau city should also not be ignorable, due to the appropriate temperature and strong solar radiation, which can promote the atmospheric photochemical reactions.展开更多
Monthly particle-phase ambient samples collected at six sampling locations in Yuxi,a high-altitude city on the edge of Southeast Asia,were measured for particle-associated PAHs.As trace substances,polycyclic aromatic ...Monthly particle-phase ambient samples collected at six sampling locations in Yuxi,a high-altitude city on the edge of Southeast Asia,were measured for particle-associated PAHs.As trace substances,polycyclic aromatic hydrocarbons(PAHs)are susceptible to the influences of meteorological conditions,emissions,and gas-particulate partitioning and it is challenging job to precise quantify the source and define the transmission path.The daily concentrations of total PM_(2.5)-bound PAHs ranged from 0.65 to 80.76 ng/m^(3),with an annual mean of 11.94 ng/m^(3).Here,we found that the concentration of PM_(2.5)-bound PAHs in winter was significantly higher than that in summer,which was mainly due to source and meteorology influence.The increase of fossil combustion and biomass burning in cold season became the main contributors of PAHs,while precipitation and low temperature exacerbated this difference.According to the concentration variation trend of PM_(2.5)-bound PAHs and their relationship with meteorological conditions,a new grouping of PAHs is applied,which suggested that PAHs have different environmental fates and migration paths.A combination of source analysis and trajectory model supported local sources from combustion of fossil fuel and vehicle exhaust contributed to the major portion on PAHs in particle,but on the Indochina Peninsula the large number of pollutants emitted by biomass burning during the fire season would affect the composition of PAHs through long-range transporting.Risk assessment in spatial and temporal variability suggested that citizens living in industrial areas were higher health risk caused by exposure the PM_(2.5)-bound PAHs than that in other regions,and the risk in winter was three times than in summer.展开更多
基金supported by the Science and Technology Program of Guangdong Province(2022B1111010004,2021B1212030015)China Agriculture Research System of MOF and MARA(CARS-41)China National Animal Disease Surveillance and Epidemiological Survey Program(2021–2025)(No.202111).
文摘The recent concurrent emergence of H5N1,H5N6,and H5N8 avian influenza viruses(AIVs)has led to significant avian mortality globally.Since 2020,frequent human-animal interactions have been documented.To gain insight into the novel H5 subtype AIVs(i.e.,H5N1,H5N6 and H5N8),we collected 6102 samples from various regions of China between January 2021 and September 2022,and identified 41 H5Nx strains.Comparative analyses on the evolution and biological properties of these isolates were conducted.Phylogenetic analysis revealed that the 41 H5Nx strains belonged to clade 2.3.4.4b,with 13 related to H5N1,19 to H5N6,and 9 to H5N8.Analysis based on global 2.3.4.4b viruses showed that all the viruses described in this study were likely originated from H5N8,exhibiting a heterogeneous evolutionary history between H5N1 and H5N6 during 2015–2022 worldwide.H5N1 showed a higher rate of evolution in 2021–2022 and more sites under positive selection pressure in 2015–2022.The antigenic profiles of the novel H5N1 and H5N6 exhibited notable variations.Further hemagglutination inhibition assay suggested that some A(H5N1)viruses may be antigenically distinct from the circulating H5N6 and H5N8 strains.Mammalian challenge assays demonstrated that the H5N8 virus(21GD001_H5N8)displayed the highest pathogenicity in mice,followed by the H5N1 virus(B1557_H5N1)and then the H5N6 virus(220086_H5N6),suggesting a heterogeneous virulence profile of H5 AIVs in the mammalian hosts.Based on the above results,we speculate that A(H5N1)viruses have a higher risk of emergence in the future.Collectively,these findings unveil a new landscape of different evolutionary history and biological characteristics of novel H5 AIVs in clade 2.3.4.4b,contributing to a better understanding of designing more effective strategies for the prevention and control of novel H5 AIVs.
基金This study was fimded by the Society Development Science Plan in Yunnan （2012CA016）, the National Natural Science Foundation of China （Grant Nos. 21567012 and 21207055）.
文摘A sampling campaign including summer, autumn and winter of 2014 and spring of 2015 was accomplished to obtain the characteristic of chemical components in PM2.5 at three sites ofKunming, a plateau city in South-west China. Nine kinds of water-soluble inorganic ions （WSI）, organic and element carbon （OC and EC） in PM2.5 were analyzed by ion chromatography and thermal optical reflectance method, respectively. Results showed that the average concentrations of total WSI, OC and EC were 22.85±10.95 μg.m -3, 17.83±9.57 μg.m-3 and 5.114-4.29 μg.m-3, respectively. They totally accounted for 53.0% of PM2.5. Secondary organic and inorganic aerosols （SOA and SIA） were also assessed by the minimum ratio of OC/EC, nitrogen and sulfur oxidation ratios. The annual average concentrations of SOA and SIA totally accounted for 28.3% of the PM2.5 concentration. The low proportion suggested the primary emission was the main source of PM2.5 in Kunming. However, secondary pollution in the plateau city should also not be ignorable, due to the appropriate temperature and strong solar radiation, which can promote the atmospheric photochemical reactions.
基金supported by the National Key R&D Projects of China(No.2019YFC0214405)the National Natural Science Foundation of China(Nos.21966016,21667014).
文摘Monthly particle-phase ambient samples collected at six sampling locations in Yuxi,a high-altitude city on the edge of Southeast Asia,were measured for particle-associated PAHs.As trace substances,polycyclic aromatic hydrocarbons(PAHs)are susceptible to the influences of meteorological conditions,emissions,and gas-particulate partitioning and it is challenging job to precise quantify the source and define the transmission path.The daily concentrations of total PM_(2.5)-bound PAHs ranged from 0.65 to 80.76 ng/m^(3),with an annual mean of 11.94 ng/m^(3).Here,we found that the concentration of PM_(2.5)-bound PAHs in winter was significantly higher than that in summer,which was mainly due to source and meteorology influence.The increase of fossil combustion and biomass burning in cold season became the main contributors of PAHs,while precipitation and low temperature exacerbated this difference.According to the concentration variation trend of PM_(2.5)-bound PAHs and their relationship with meteorological conditions,a new grouping of PAHs is applied,which suggested that PAHs have different environmental fates and migration paths.A combination of source analysis and trajectory model supported local sources from combustion of fossil fuel and vehicle exhaust contributed to the major portion on PAHs in particle,but on the Indochina Peninsula the large number of pollutants emitted by biomass burning during the fire season would affect the composition of PAHs through long-range transporting.Risk assessment in spatial and temporal variability suggested that citizens living in industrial areas were higher health risk caused by exposure the PM_(2.5)-bound PAHs than that in other regions,and the risk in winter was three times than in summer.
