We investigate the fluorene-vinylene unit dependent photo-physical properties of multi- branched truxene based oligomers （Tr-OFVn, n=1-4） employing steady-state absorption and emission spectroscopy, transient absorp...We investigate the fluorene-vinylene unit dependent photo-physical properties of multi- branched truxene based oligomers （Tr-OFVn, n=1-4） employing steady-state absorption and emission spectroscopy, transient absorption spectroscopy, two-photon fluorescence, and z-scan technique. The results show that the increasing of fluorene-vinylene unit leads to a red-shift in the spectra of absorption and fluorescence, and shortens the excited state lifetime. Meanwhile, two-photon fluorescence efficiency and two-photon absorption cross section of truxene based oligolners gradually enhance in company with the extension of π- conjugated length. In addition, the values of two-photon absorption cross section modeled on the sum-over-state approach agree well with the experimental ones. The results indicate multi-branched truxene based oligomers bearing organic materials for two-photon applications.展开更多
Objective To clarify the epidemiological characteristics and spatial distribution patterns of human norovirus outbreaks in China, identify high-risk areas, and provide guidance for epidemic prevention and control.Meth...Objective To clarify the epidemiological characteristics and spatial distribution patterns of human norovirus outbreaks in China, identify high-risk areas, and provide guidance for epidemic prevention and control.Methods This study analyzed 964 human norovirus outbreaks involving 50,548 cases in 26 provinces reported from 2012 to 2018. Epidemiological analysis and spatiotemporal scanning analysis were conducted to analyze the distribution of norovirus outbreaks in China.Results The outbreaks showed typical seasonality, with more outbreaks in winter and fewer in summer, and the total number of infected cases increased over time. Schools, especially middle schools and primary schools, are the most common settings of norovirus outbreaks, with the major transmission route being life contact. More outbreaks occurred in southeast coastal areas in China and showed significant spatial aggregation. The highly clustered areas of norovirus outbreaks have expanded northeast over time.Conclusion By identifying the epidemiological characteristics and high-risk areas of norovirus outbreaks, this study provides important scientific support for the development of preventive and control measures for norovirus outbreaks, which is conducive to the administrative management of high-risk settings and reduction of disease burden in susceptible areas.展开更多
BACKGROUND Hypoplasia of bilateral cruciate ligaments is a rare congenital malformation.The diagnosis of such diseases and indications for the various treatment options require further analysis and discussion.CASE SUM...BACKGROUND Hypoplasia of bilateral cruciate ligaments is a rare congenital malformation.The diagnosis of such diseases and indications for the various treatment options require further analysis and discussion.CASE SUMMARY The patient is a 26-year-old Chinese woman who has been suffering from knee pain since the age of 8 years,2-3 episodes a year.Three years ago,due to the practice of advanced yoga poses,the frequency of left knee pain increased,requiring prompt medical treatment.Magnetic resonance imaging demonstrated an absence of both anterior and posterior cruciate ligaments of both knees with abnormal posterior tilting of the tibial plateau.Bilateral subluxation of the knee joint was also found,therefore tibial osteotomy was performed.The patient reported at the 24 mo follow-up that the frequency of pain and instability had been reduced and function restored.CONCLUSION Osteotomy may be an effective method to treat patients with congenital cruciate ligament deficiency with posterior tibial plateau tilting.The diagnosis of congenital cruciate ligament deficiency shall be based on the combination of patient’s medical history,clinical manifestations,and findings from imaging to avoid possible misdiagnosis.Based on the symptoms,frequency of attacks,and intent of the individual,appropriate treatment options shall be identified.展开更多
文摘We investigate the fluorene-vinylene unit dependent photo-physical properties of multi- branched truxene based oligomers （Tr-OFVn, n=1-4） employing steady-state absorption and emission spectroscopy, transient absorption spectroscopy, two-photon fluorescence, and z-scan technique. The results show that the increasing of fluorene-vinylene unit leads to a red-shift in the spectra of absorption and fluorescence, and shortens the excited state lifetime. Meanwhile, two-photon fluorescence efficiency and two-photon absorption cross section of truxene based oligolners gradually enhance in company with the extension of π- conjugated length. In addition, the values of two-photon absorption cross section modeled on the sum-over-state approach agree well with the experimental ones. The results indicate multi-branched truxene based oligomers bearing organic materials for two-photon applications.
基金supported by the National Natural Science Foundation of China[grant number 81903377]Young Scholar Foundation of NIEH[grant number 19qnjj]。
文摘Objective To clarify the epidemiological characteristics and spatial distribution patterns of human norovirus outbreaks in China, identify high-risk areas, and provide guidance for epidemic prevention and control.Methods This study analyzed 964 human norovirus outbreaks involving 50,548 cases in 26 provinces reported from 2012 to 2018. Epidemiological analysis and spatiotemporal scanning analysis were conducted to analyze the distribution of norovirus outbreaks in China.Results The outbreaks showed typical seasonality, with more outbreaks in winter and fewer in summer, and the total number of infected cases increased over time. Schools, especially middle schools and primary schools, are the most common settings of norovirus outbreaks, with the major transmission route being life contact. More outbreaks occurred in southeast coastal areas in China and showed significant spatial aggregation. The highly clustered areas of norovirus outbreaks have expanded northeast over time.Conclusion By identifying the epidemiological characteristics and high-risk areas of norovirus outbreaks, this study provides important scientific support for the development of preventive and control measures for norovirus outbreaks, which is conducive to the administrative management of high-risk settings and reduction of disease burden in susceptible areas.
文摘BACKGROUND Hypoplasia of bilateral cruciate ligaments is a rare congenital malformation.The diagnosis of such diseases and indications for the various treatment options require further analysis and discussion.CASE SUMMARY The patient is a 26-year-old Chinese woman who has been suffering from knee pain since the age of 8 years,2-3 episodes a year.Three years ago,due to the practice of advanced yoga poses,the frequency of left knee pain increased,requiring prompt medical treatment.Magnetic resonance imaging demonstrated an absence of both anterior and posterior cruciate ligaments of both knees with abnormal posterior tilting of the tibial plateau.Bilateral subluxation of the knee joint was also found,therefore tibial osteotomy was performed.The patient reported at the 24 mo follow-up that the frequency of pain and instability had been reduced and function restored.CONCLUSION Osteotomy may be an effective method to treat patients with congenital cruciate ligament deficiency with posterior tibial plateau tilting.The diagnosis of congenital cruciate ligament deficiency shall be based on the combination of patient’s medical history,clinical manifestations,and findings from imaging to avoid possible misdiagnosis.Based on the symptoms,frequency of attacks,and intent of the individual,appropriate treatment options shall be identified.
