A highly sensitive fluorescence spectroscopic method was established for the selective determination of estradiol, which took advantages of the excellent molecular recognition capability of aptamer and the energy transfer between the specific fluorescent groups. The effects of the pH value, buffer constituent and concentration, the concentration of DNA, the experimental temperature and response time on the detection of estradiol were studied. Under the optimal conditions (50 mmol/L BR buffer solution with pH value at 7. 4, 1. 0×10-7 mol/L for each DNA strand, incubation at 45 ℃, response time 19 min), the change of the fluorescence intensity (ΔI) versus the logarithm of the concentration of estradiol ( lgC) was linear over a concentration range from 1. 0×10-11 mol/L to 5. 0×10-9 mol/L with good linear correlation (r=0. 9953). The limit of detection (LOD) was found to be 6. 0×10-12 mol/L (S/N=3). This method was successfully applied to the detection of estradiol in human urine, with the recovery in the range of 94. 0%-103. 5%. This method showed good precision and accuracy.

How to promote rapid wound healing and reduce scar hyperplasia is an urgent problem to be solved in plastic surgery. Mesenchymal stem cells (MSCs) is a research hotspot in current cell therapy. The author reviewed the literature and summarized the mechanism of the MSCs effect on the macrophage. MSCs release multiple soluble cytokines, leading the polarization of anti-inflammatory type M2 cell which can reduce the inflammatory cytokines and promote tissue repair and regeneration.The writer concluded that the polarization effect of mesenchymal stem cells on macrophages provides a new therapeutic strategy and theoretical basis for solving the problem of wound healing.

Objective:To investigate the psychological stress and related factors of community medical staff in Shanghai during infectious public health emergencies.Methods:Random cluster sampling, questionnaires combining general demographic information, self-rating anxiety scale(SAS), self-rating depression scale(SDS)and yale-brown obsessive compulsive scale(YB)were administrated to investigate the psychological stress of medical staff from 20 community healthcare centers in 10 Shanghai districts.Results:A total of 696 valid questionnaires were collected. 17.36% of the staff had SAS scores exceeding the boundary value. Nurses, staff with per capita monthly family income<5 000 yuan, or with below-average family relations presented higher SAS scores. 28.19% of the staff had SDS scores exceeding the boundary value. Staff with 5-10 years seniority, nurses, with per capita monthly family income<5 000 yuan, and with poor family relations presented higher SDS scores. 6.68% of the staff had YB score≥16. Nurses presented a higher YB score.Conclusions:Some community healthcare center staff experienced psychological stress during public health emergencies.Factors associated with psychological stress, such as 5-10 years′ seniority, nurses, per capita monthly family income<5 000 yuan, below-average or poor family relations, deserve more attention in order to prevent from or alleviate harmful psychological stress.