Objective To investigate the roles of TrkA and TrkB in radiation-induced hippocampal neurogenesis impairment.Methods Fifty-six rats were randomized into radiation group and sham control group.Radiation group received whole brain irradiation at a single dose of 10 Gy.The hippocampus were separated from rats in day 1,day 3,day 14 and 1 month after irradiation.Western blot and RT-PCR were applied to detect the protein levels and mRNA levels.Golgi staining was used to observe the dendritic spine of hippocampus.Immunofluorescence was performed to detect neural precursor's proliferation.Results Compared with control group,the numbers of dendritic spine significantly decreased after irradiation and its shape change obviously.Immunofluorescence showed a significant decrease in neural precursor's proliferation comparing with control group (t =6.49,P ＜ 0.05).Protein level of TrkA expression increased (t =2.64,3.06,4.80,2.64,P ＜ 0.05),while the levels of TrkB protein expression decreased significantly (t =4.59,3.06,2.81,2.57,P ＜ 0.05).The mRNA level of TrkA expressions increased (t =4.57,3.06,5.39,5.86,P ＜ 0.05),while the mRNA level of TrkB decreased (t =14.87,11.69,4.98,P ＜ 0.05).Conclusions As a signaling pathways downstream of NGF and BDNF,TrkA and TrkB may play an important role in radiation-induced neurogenesis impairment.

Objective:To explore the psychometric characteristics of the Chinese version of the health-related social capital scale.Methods:From March to May 2020, after the original scale was translated into Chinese following the Brislin improved translation model, 251 community-dwelling senior citizens aged 65 and above were selected by convenient sampling method. Data analysis was conducted using SPSS 22.0 and AMOS 22.0, including tests of significance, correlation analysis, exploratory factor analysis, and confirmatory factor analysis.Results:Exploratory factor analysis extracted three factors: social participation, social cohesion, and reciprocity, which accounted for a cumulative contribution rate of 61.72%. Confirmatory factor analysis showed that the three-factor model fitted well(χ 2/ df=1.22, RMSEA=0.04, CFI=0.98, GFI=0.93, IFI=0.98, TLI=0.97). Social capital was significantly correlated with perceived social support positively ( r=0.36, P<0.01), and with loneliness negatively ( r=-0.30, P<0.01). The three factors were significantly correlated with the total scale ( r=0.85, 0.50 and 0.52, respectively, all P<0.01). And correlations between the items of each factor were 0.24-0.55, 0.30-0.59, 0.44-0.70, respectively(all P<0.01). The Cronbach's α coefficients of the total scale and three factors were 0.74, 0.72, 0.65 and 0.62, respectively(all P<0.01), and their retest reliability were 0. 92, 0. 87, 0. 82 and 0. 96, respectively(all P<0.01). Conclusion:The Chinese version of health-related social capital scale conforms to the three-factor model with good reliability and validity, which can be used to assess the social capital status of community-dwelling older adults in China.