Background: Children with seasonal influenza infection cause a significant burden of disease each year in the pediatric clinic. Influenza A and B viruses are the major types responsible for illness. A better understan...Background: Children with seasonal influenza infection cause a significant burden of disease each year in the pediatric clinic. Influenza A and B viruses are the major types responsible for illness. A better understanding of the periodicity facilitates the prevention and control of influenza in children. Objective: This study aims to analyze the epidemiological patterns and subtype characterization of influenza viruses among children in Shenzhen, China. Methods: Influenza samples were collected by nasopharyngeal swabs from influenza like illness patients in Shenzhen Children’s Hospital from January 2016 to December 2018. The positive cases and influenza subtypes were determined by gold labeled antigen detection and reverse transcriptase polymerase chain reaction. The influenza periodicity and age, subtype distribution as well as the association between climate parameters and different influenza subtypes were analyzed by SPSS 22.0. Results: The influenza positive rate during 2016-2018 was 21.0%, with a highest positive rate in the year 2018. The positive rate varied by month, season, and year describing a sequence of peaks presenting primarily in all year including spring, summer and winter. The characteristics of influenza peak were different in each year, with a spring peak in 2016 and a summer plus a winter-spring peaks in 2017 and 2018. In addition, influenza B exhibited a winter-spring seasonal pattern while influenza A displayed a more variable seasonality, highlighting influenza B rather than influenza A which had a negative association with climate parameters. Influenza-positive cases were older than influenza-negative cases (P P Conclusion: Influenza activity in children from Shenzhen typically displays both winter-spring and summer peaks. Influenza A epidemic occurred separately or co-circulated with influenza B, with a winter-spring pattern for influenza B and a much more variable seasonality for influenza A. Influenza B had a negative association with climate parameters. In addition, hospitalization with influenza often occurs in younger individuals infected with influenza A.展开更多
The authors study the Cauchy problem for the focusing nonlinear KunduEckhaus(KE for short)equation and construct the long time asymptotic expansion of its solution in fixed space-time cone with C(x_(1),x_(2),v_(1),v_(...The authors study the Cauchy problem for the focusing nonlinear KunduEckhaus(KE for short)equation and construct the long time asymptotic expansion of its solution in fixed space-time cone with C(x_(1),x_(2),v_(1),v_(2))={(x,t)∈R^(2):x=x_(0)+vt,x_(0)∈[x_(1),x_(2)],v∈[v_(1),v_(2)]}.By using the inverse scattering transform,Riemann-Hilbert approach and δ steepest descent method,they obtain the lone time asymptotic behavior of the solution,at the same time,they obtain the solitons in the cone compare with the all N-soliton the residual error up to order O(t-^(3/4)).展开更多
文摘Background: Children with seasonal influenza infection cause a significant burden of disease each year in the pediatric clinic. Influenza A and B viruses are the major types responsible for illness. A better understanding of the periodicity facilitates the prevention and control of influenza in children. Objective: This study aims to analyze the epidemiological patterns and subtype characterization of influenza viruses among children in Shenzhen, China. Methods: Influenza samples were collected by nasopharyngeal swabs from influenza like illness patients in Shenzhen Children’s Hospital from January 2016 to December 2018. The positive cases and influenza subtypes were determined by gold labeled antigen detection and reverse transcriptase polymerase chain reaction. The influenza periodicity and age, subtype distribution as well as the association between climate parameters and different influenza subtypes were analyzed by SPSS 22.0. Results: The influenza positive rate during 2016-2018 was 21.0%, with a highest positive rate in the year 2018. The positive rate varied by month, season, and year describing a sequence of peaks presenting primarily in all year including spring, summer and winter. The characteristics of influenza peak were different in each year, with a spring peak in 2016 and a summer plus a winter-spring peaks in 2017 and 2018. In addition, influenza B exhibited a winter-spring seasonal pattern while influenza A displayed a more variable seasonality, highlighting influenza B rather than influenza A which had a negative association with climate parameters. Influenza-positive cases were older than influenza-negative cases (P P Conclusion: Influenza activity in children from Shenzhen typically displays both winter-spring and summer peaks. Influenza A epidemic occurred separately or co-circulated with influenza B, with a winter-spring pattern for influenza B and a much more variable seasonality for influenza A. Influenza B had a negative association with climate parameters. In addition, hospitalization with influenza often occurs in younger individuals infected with influenza A.
文摘The authors study the Cauchy problem for the focusing nonlinear KunduEckhaus(KE for short)equation and construct the long time asymptotic expansion of its solution in fixed space-time cone with C(x_(1),x_(2),v_(1),v_(2))={(x,t)∈R^(2):x=x_(0)+vt,x_(0)∈[x_(1),x_(2)],v∈[v_(1),v_(2)]}.By using the inverse scattering transform,Riemann-Hilbert approach and δ steepest descent method,they obtain the lone time asymptotic behavior of the solution,at the same time,they obtain the solitons in the cone compare with the all N-soliton the residual error up to order O(t-^(3/4)).
