Tion. This study indicated age groups at higher risk of hospitalization during the inhibitor immediate post-pandemic period were changing, compared with those during the 2009?010 pandemic. During the winter season of 2010?011, children under 5 years had the highest risk of hospitalization and death associated withHospitalized Cases of 2009 H1N1 after PandemicH1N1 infection. Additionally, a decline of risk of hospitalization among people aged 5?4 years and a shift to older age for fatal patients was detected. The relative risk of hospitalization and death among people older than 64 years increased. Consistent with seasonal influenza and the 2009?010 pandemic period, chronic medical conditions are important risk factors for severe disease during the winter season of 2010?011. This study demonstrated the benefit of maintenance of severe patients surveillance to determine changes in the epidemiology of 2009 H1N1 infection after the pandemic period, and contributing to recommendations to target groups for 25331948 influenza prevention and control interventions.Figure S2 Age distribution of hospitalized caseswith and without chronic medical conditions, the 2010?011 winter season. Bar labels denote percent of hospitalized cases with chronic medical conditions in each age group. 15900046 (TIF)AcknowledgmentsWe thank the participating hospitals, local health departments and Centers for Disease Control and Prevention in China for assistance in coordinating data collection, and the Ministry of Health, China for supporting this study.Supporting InformationGeographical distribution of all hospitalized cases reported to China CDC, China, from November 2010 to May 2011. (TIF)Figure SAuthor ContributionsConceived and designed the experiments: CX YS. Performed the experiments: CX MC TC JS JY LW FY. Analyzed the data: CX P-YC ADI. Contributed reagents/materials/analysis tools: CX MC TC JS LW FY. Wrote the paper: CX ADI YS M-AW.
The stability of DNA largely depends on the accuracy of its repair systems, which remove DNA damage induced by exogenous and 
endogenous agents or introduced by DNA metabolism, such as replication [1,2]. If unrepaired or misrepaired, DNA damage can cause 
cell death. To mend the many different types of DNA damage, cells utilize DNA repair systems, including homologous recombination repair (HR), mismatch repair (MMR), and excision repair (NER, BER) [3,4]. Archaea, the third domain of life, has DNA replication factors that resemble those in Eukarya with respect to the amino acid sequences, suggesting that the mechanisms of DNA replication would be similar in eukaryotic and archaeal cells [5?7]. The DNA repair proteins are also conserved between Archaea and Eukarya, and structural studies of the archaeal homologs have yielded numerous important insights into the structures and functions of eukaryotic DNA repair proteins [8?12]. In addition, the DNA repair systems in the hyperthermophilic archaea are especially attractive to investigate, for understanding the phenomena allowing life to exist at extremely high temperatures. It has been suggested that thermophiles must have extremely inhibitor efficient and specialized DNA repair systems to withstand not only the high temperatures but also other damaging factors, such as ionizing and ultraviolet radiation and chemical agents. The spontaneous mutation rate isaccelerated at elevated temperatures, due to the formation of lesions in the DNA bases [13?5]. Pyrococcus furiosus is a hyperthermophilic archaeon that optimally grows at o.Tion. This study indicated age groups at higher risk of hospitalization during the immediate post-pandemic period were changing, compared with those during the 2009?010 pandemic. During the winter season of 2010?011, children under 5 years had the highest risk of hospitalization and death associated withHospitalized Cases of 2009 H1N1 after PandemicH1N1 infection. Additionally, a decline of risk of hospitalization among people aged 5?4 years and a shift to older age for fatal patients was detected. The relative risk of hospitalization and death among people older than 64 years increased. Consistent with seasonal influenza and the 2009?010 pandemic period, chronic medical conditions are important risk factors for severe disease during the winter season of 2010?011. This study demonstrated the benefit of maintenance of severe patients surveillance to determine changes in the epidemiology of 2009 H1N1 infection after the pandemic period, and contributing to recommendations to target groups for 25331948 influenza prevention and control interventions.Figure S2 Age distribution of hospitalized caseswith and without chronic medical conditions, the 2010?011 winter season. Bar labels denote percent of hospitalized cases with chronic medical conditions in each age group. 15900046 (TIF)AcknowledgmentsWe thank the participating hospitals, local health departments and Centers for Disease Control and Prevention in China for assistance in coordinating data collection, and the Ministry of Health, China for supporting this study.Supporting InformationGeographical distribution of all hospitalized cases reported to China CDC, China, from November 2010 to May 2011. (TIF)Figure SAuthor ContributionsConceived and designed the experiments: CX YS. Performed the experiments: CX MC TC JS JY LW FY. Analyzed the data: CX P-YC ADI. Contributed reagents/materials/analysis tools: CX MC TC JS LW FY. Wrote the paper: CX ADI YS M-AW.
The stability of DNA largely depends on the accuracy of its repair systems, which remove DNA damage induced by exogenous and endogenous agents or introduced by DNA metabolism, such as replication [1,2]. If unrepaired or misrepaired, DNA damage can cause cell death. To mend the many different types of DNA damage, cells utilize DNA repair systems, including homologous recombination repair (HR), mismatch repair (MMR), and excision repair (NER, BER) [3,4]. Archaea, the third domain of life, has DNA replication factors that resemble those in Eukarya with respect to the amino acid sequences, suggesting that the mechanisms of DNA replication would be similar in eukaryotic and archaeal cells [5?7]. The DNA repair proteins are also conserved between Archaea and Eukarya, and structural studies of the archaeal homologs have yielded numerous important insights into the structures and functions of eukaryotic DNA repair proteins [8?12]. In addition, the DNA repair systems in the hyperthermophilic archaea are especially attractive to investigate, for understanding the phenomena allowing life to exist at extremely high temperatures. It has been suggested that thermophiles must have extremely efficient and specialized DNA repair systems to withstand not only the high temperatures but also other damaging factors, such as ionizing and ultraviolet radiation and chemical agents. The spontaneous mutation rate isaccelerated at elevated temperatures, due to the formation of lesions in the DNA bases [13?5]. Pyrococcus furiosus is a hyperthermophilic archaeon that optimally grows at o.