Porcine deltacoronavirus(PDCoV) is a newly identified virus that causes watery diarrhea in newborn piglets and results in significant economic losses to the pig industry. Since first reported in Hong Kong in 2012, PDC...Porcine deltacoronavirus(PDCoV) is a newly identified virus that causes watery diarrhea in newborn piglets and results in significant economic losses to the pig industry. Since first reported in Hong Kong in 2012, PDCoV has been subsequently detected in USA, South Korea, Thailand, and China's Mainland. Here we isolated a strain of PDCoV, named CHN-GD-2016,from the intestinal content of a diseased newborn piglet with severe diarrhea in a pig farm in Guangdong, China. PDCoV CHN-GD-2016 could be identified by immunofluorescence with PDCoV specific rabbit antisera, and typical crown-shaped particles with spiky surface projections of this PDCoV were observed with electron microscopy. Genomic analysis showed that the PDCoV CHN-GD-2016 was closely related to other Chinese PDCoV strains, with the highest sequence similarity with the strain CHN/Tianjin/2016. Importantly, inoculation of newborn piglets with 1×10~5 TCID_(50) of CHN-GD-2016 by oral feeding successfully reproduced clear clinical symptoms, including vomiting, dehydration, and severe diarrhea in piglets. In addition, the virus RNA in rectal swabs from 1 to 7 days post inoculation was detected, macroscopic and microscopic lesions in small intestine were observed, and viral antigen was also detected in the small intestines with immunohistochemical staining. Collectively, the data show in this study confirms that PDCoV is present in Guangdong,China and is highly pathogenic in newborn piglets.展开更多
Since 2012,the clinical cases of inclusion body hepatitis showed an increasing trend in China,causing considerable economic losses to the poultry industry.In this study,a fowl adenovirus strain CH/GDLZ/201801 was isol...Since 2012,the clinical cases of inclusion body hepatitis showed an increasing trend in China,causing considerable economic losses to the poultry industry.In this study,a fowl adenovirus strain CH/GDLZ/201801 was isolated from a chicken flock experiencing inclusion body hepatitis and analyzed by complete genome sequencing.The pathogenicity of the new virus strain was examined by experimental infection of specific pathogen free chickens.The isolate was identified by immunofluorescence and the virions presented typical icosahedral particles under transmission electron microscopy.The full genome of the isolate was 44,329 nucleotides in length with 58%G+C content.Phylogenetic analysis,based on the whole genome,revealed that the new isolate was closest to serotype 8a from the species Fowl aviadenovirus E(FAdVE).Recombination analysis and phylogenetic analysis showed that the new isolate is a recombinant strain between FAdV-8a and FAdV-8b.In infection experiments,three infected chickens showed clinical signs and one chicken died on day 7 post infection,corresponding to 5%mortality.Macroscopic and microscopic lesions in the liver were observed,and viral antigen could be detected in the livers by immunohistochemical staining and TEM.Taken together,our study describes the genomic characteristics and pathogenicity of a FAdV-8a strain in China.It would lay a solid foundation for further study of the pathogenic mechanism and vaccine development of the virus.展开更多
Nowadays,crowded environment and high-speed life pace are likely to bring mental stress and fatigue to citizens.How to apply achievements of the restorative environment into urban planning and environmental design has...Nowadays,crowded environment and high-speed life pace are likely to bring mental stress and fatigue to citizens.How to apply achievements of the restorative environment into urban planning and environmental design has received more attention in recent years.Earlier research does not provide detailed information about the specific components of the physical environment that support restoration.This study explores which characteristics of the street environment and psychological factors of the street environment have an impact on subjective restoration.The streets were sampled from Shenzhen.Each street was represented by a single photo.The photo was quantified in terms of the different objective street components and also rated on psychological variables related to restoration.The rating on the psychological variables,being away,fascination,coherence,scope,the likelihood of restoration,and preference were provided by people of various ages and occupations.The results show that:1)the proportion of natural elements have the greatest impact on street restoration benefits and preference,and its impact is robust;2)the two characteristics of street safety and quiet are important to street restoration benefits and preferences;3)fascination and being away have a greater impact on restorative benefits of streets,followed by coherence,and the scope of the street has no significant effect on restorative benefits.The study could provide evidence for policy-makers and urban design and planning interventions.展开更多
Photocatalytic water splitting with simultaneous degradation of organic pollutants is an effective strategy to alleviate the increasingly serious energy and environmental crisis.However,the photocatalytic activity is ...Photocatalytic water splitting with simultaneous degradation of organic pollutants is an effective strategy to alleviate the increasingly serious energy and environmental crisis.However,the photocatalytic activity is restricted by the high charge recombination rate and limited sunlight utilization.Herein,black phosphorus(BP)with a broad sunlight response range was utilized as a photosensitizer to enhance the photocatalytic performance of the Au/carbon nitride(CN)heterostructure.The as-prepared BP/Au/CN exhibited a significantly enhanced H_(2) generation rate of 1400.8µmol h^(−1) g^(−1) under UV-vis light irradiation,which is almost 70 times higher than that of bare CN and BP/CN and 2 folds higher than that of the Au/CN heterojunction.Specifically,the optimal BP/Au/CN sample presented a waste-to-hydrogen production rate of 195.8µmol h^(−1) g^(−1) with the degradation of bisphenol A,verifying the synergistic effect of the ternary heterojunction.The photocatalytic mechanism was systematically studied by the combination of experiments and theoretical calculations.The improved photocatalytic performance was derived from the overall sunlight absorption ability of BP,effective electron transfer media and plasmonic character of Au nanoparticles,as well as the matched work function and strong interaction of the three components.A unidirectional electron transfer from BP to Au and then to CN was established,which effectively improved the charge transfer capability,resulting from the appropriate Ohmic contact of Au and BP and the Schottky barrier constructed in Au/CN hybrid.展开更多
Accurate simulations of planetary boundary layer(PBL)winds in urban areas require combining meteorological knowledge and fine-grained geometrical information.Computational fluid dynamics(CFD)is widely used to assess p...Accurate simulations of planetary boundary layer(PBL)winds in urban areas require combining meteorological knowledge and fine-grained geometrical information.Computational fluid dynamics(CFD)is widely used to assess pedestrian wind comfort and wind disasters in planning resilient cities.However,the CFD-predicted PBL is highly affected by the inflow boundaries.Wind profiles under extreme weather conditions,such as tropical cyclones,can hardly be determined,and associated uniform logarithmic or power law expressions have not been obtained.In this study,urban wind flow over mountainous terrain was simulated using a one-way nested simulation approach between mesoscale and microscale models.The inflow wind speed,turbulence scalars,and potential temperature in the CFD code are sustained by the numerical weather prediction(NWP)model.Methodologies considering typhoon weather conditions were examined to improve the numerical accuracy in determining mesoscale typhoon structures and pedestrian-level wind conditions.The numerical errors were quantified in mesoscale and microscale formulations.A new tendency assimilation was proposed by incorporating local-scale observations into the CFD domain.This approach entailed empirical mode decomposition to quantify the mean wind speed differences between the observations and NWP results,which were then extrapolated to NWP-CFD nested interfaces via multiplication by the spatial correlation coefficient.The numerical performance was validated against both on-site observations for meteorological purposes and wind profiles retrieved from the experimental LiDAR of the landfalling typhoon Haima.The simulated wind field exhibited an increased accuracy in the local urban area.More specifically,the index of agreement in wind speeds was improved from 0.28 to 0.72,and the mean absolute errors were reduced from 5.46 m/s to 1.89 m/s.展开更多
基金supported by the National Key Research and Development Program (2016YFD0500101)
文摘Porcine deltacoronavirus(PDCoV) is a newly identified virus that causes watery diarrhea in newborn piglets and results in significant economic losses to the pig industry. Since first reported in Hong Kong in 2012, PDCoV has been subsequently detected in USA, South Korea, Thailand, and China's Mainland. Here we isolated a strain of PDCoV, named CHN-GD-2016,from the intestinal content of a diseased newborn piglet with severe diarrhea in a pig farm in Guangdong, China. PDCoV CHN-GD-2016 could be identified by immunofluorescence with PDCoV specific rabbit antisera, and typical crown-shaped particles with spiky surface projections of this PDCoV were observed with electron microscopy. Genomic analysis showed that the PDCoV CHN-GD-2016 was closely related to other Chinese PDCoV strains, with the highest sequence similarity with the strain CHN/Tianjin/2016. Importantly, inoculation of newborn piglets with 1×10~5 TCID_(50) of CHN-GD-2016 by oral feeding successfully reproduced clear clinical symptoms, including vomiting, dehydration, and severe diarrhea in piglets. In addition, the virus RNA in rectal swabs from 1 to 7 days post inoculation was detected, macroscopic and microscopic lesions in small intestine were observed, and viral antigen was also detected in the small intestines with immunohistochemical staining. Collectively, the data show in this study confirms that PDCoV is present in Guangdong,China and is highly pathogenic in newborn piglets.
文摘Since 2012,the clinical cases of inclusion body hepatitis showed an increasing trend in China,causing considerable economic losses to the poultry industry.In this study,a fowl adenovirus strain CH/GDLZ/201801 was isolated from a chicken flock experiencing inclusion body hepatitis and analyzed by complete genome sequencing.The pathogenicity of the new virus strain was examined by experimental infection of specific pathogen free chickens.The isolate was identified by immunofluorescence and the virions presented typical icosahedral particles under transmission electron microscopy.The full genome of the isolate was 44,329 nucleotides in length with 58%G+C content.Phylogenetic analysis,based on the whole genome,revealed that the new isolate was closest to serotype 8a from the species Fowl aviadenovirus E(FAdVE).Recombination analysis and phylogenetic analysis showed that the new isolate is a recombinant strain between FAdV-8a and FAdV-8b.In infection experiments,three infected chickens showed clinical signs and one chicken died on day 7 post infection,corresponding to 5%mortality.Macroscopic and microscopic lesions in the liver were observed,and viral antigen could be detected in the livers by immunohistochemical staining and TEM.Taken together,our study describes the genomic characteristics and pathogenicity of a FAdV-8a strain in China.It would lay a solid foundation for further study of the pathogenic mechanism and vaccine development of the virus.
文摘Nowadays,crowded environment and high-speed life pace are likely to bring mental stress and fatigue to citizens.How to apply achievements of the restorative environment into urban planning and environmental design has received more attention in recent years.Earlier research does not provide detailed information about the specific components of the physical environment that support restoration.This study explores which characteristics of the street environment and psychological factors of the street environment have an impact on subjective restoration.The streets were sampled from Shenzhen.Each street was represented by a single photo.The photo was quantified in terms of the different objective street components and also rated on psychological variables related to restoration.The rating on the psychological variables,being away,fascination,coherence,scope,the likelihood of restoration,and preference were provided by people of various ages and occupations.The results show that:1)the proportion of natural elements have the greatest impact on street restoration benefits and preference,and its impact is robust;2)the two characteristics of street safety and quiet are important to street restoration benefits and preferences;3)fascination and being away have a greater impact on restorative benefits of streets,followed by coherence,and the scope of the street has no significant effect on restorative benefits.The study could provide evidence for policy-makers and urban design and planning interventions.
基金supported by the National Natural Science Foundation of China(21801092,21872001,U1704140)the Program for the Development of Science and Technology of Jilin Province(20200801040GH)+3 种基金the Science and Technology Research Project of Henan Province(202102210055)the General project of Chinese postdoctoral program(2020M672263)the Key Research Programs in Universities of Henan Province(20A150031)the Science and Technology Innovation Talent Support Program of Henan Province(19HASTIT034)。
文摘Photocatalytic water splitting with simultaneous degradation of organic pollutants is an effective strategy to alleviate the increasingly serious energy and environmental crisis.However,the photocatalytic activity is restricted by the high charge recombination rate and limited sunlight utilization.Herein,black phosphorus(BP)with a broad sunlight response range was utilized as a photosensitizer to enhance the photocatalytic performance of the Au/carbon nitride(CN)heterostructure.The as-prepared BP/Au/CN exhibited a significantly enhanced H_(2) generation rate of 1400.8µmol h^(−1) g^(−1) under UV-vis light irradiation,which is almost 70 times higher than that of bare CN and BP/CN and 2 folds higher than that of the Au/CN heterojunction.Specifically,the optimal BP/Au/CN sample presented a waste-to-hydrogen production rate of 195.8µmol h^(−1) g^(−1) with the degradation of bisphenol A,verifying the synergistic effect of the ternary heterojunction.The photocatalytic mechanism was systematically studied by the combination of experiments and theoretical calculations.The improved photocatalytic performance was derived from the overall sunlight absorption ability of BP,effective electron transfer media and plasmonic character of Au nanoparticles,as well as the matched work function and strong interaction of the three components.A unidirectional electron transfer from BP to Au and then to CN was established,which effectively improved the charge transfer capability,resulting from the appropriate Ohmic contact of Au and BP and the Schottky barrier constructed in Au/CN hybrid.
基金This study was supported by the National Natural Science Foundation of China(No:51778200)Shenzhen Basic Research Program(No:JCYJ20190806145216643).
文摘Accurate simulations of planetary boundary layer(PBL)winds in urban areas require combining meteorological knowledge and fine-grained geometrical information.Computational fluid dynamics(CFD)is widely used to assess pedestrian wind comfort and wind disasters in planning resilient cities.However,the CFD-predicted PBL is highly affected by the inflow boundaries.Wind profiles under extreme weather conditions,such as tropical cyclones,can hardly be determined,and associated uniform logarithmic or power law expressions have not been obtained.In this study,urban wind flow over mountainous terrain was simulated using a one-way nested simulation approach between mesoscale and microscale models.The inflow wind speed,turbulence scalars,and potential temperature in the CFD code are sustained by the numerical weather prediction(NWP)model.Methodologies considering typhoon weather conditions were examined to improve the numerical accuracy in determining mesoscale typhoon structures and pedestrian-level wind conditions.The numerical errors were quantified in mesoscale and microscale formulations.A new tendency assimilation was proposed by incorporating local-scale observations into the CFD domain.This approach entailed empirical mode decomposition to quantify the mean wind speed differences between the observations and NWP results,which were then extrapolated to NWP-CFD nested interfaces via multiplication by the spatial correlation coefficient.The numerical performance was validated against both on-site observations for meteorological purposes and wind profiles retrieved from the experimental LiDAR of the landfalling typhoon Haima.The simulated wind field exhibited an increased accuracy in the local urban area.More specifically,the index of agreement in wind speeds was improved from 0.28 to 0.72,and the mean absolute errors were reduced from 5.46 m/s to 1.89 m/s.
