Objective:To explore the effect of perspective-taking on HIV-related stigma intervention among medical college students.Methods:192 medical college students selected from one medical college were randomly divided into experimental group and control group.Perspective-taking intervention was implemented in the experimental group.HIV-related Stigma Questionnaire was used to measure the level of HIV-related stigma before and after the intervention for two groups.Results:Before intervention,there was no significant difference in the total score of HIV-related stigma between the two groups (P ＞ 0.05);there was significant difference in the total score of HIV-related stigma between the two groups after the intervention (P ＜ 0.05).Empathy had a partial mediating effect on the relationship between perspective-taking and HIV-related stigma,and the ratio of mediation effect to total effect was 0.260.Conclusion:The perspective-taking effectively can reduce the level of HIV-related stigma through the mediation effect of empathy.

[Objective] To determine the feasibility of preparing plasminogen (Pg) with Fraction Ⅲ precipitation (hereinafter referred to as FⅢ-P) from low-temperature ethanol process by full chromatography (hereinafter referred to as FⅢ-P process). [Methods] The FⅢ-P was diluted with dissolution buffer at different dilution times and stirring time. The potency and antigen concentration of Pg in dissolution sample were detected and the dissolution and clarification conditions were determined. Pre-treatment of loading sample and pre-experiment of affinity chromatography were carried out on the FⅢ-P dissolution sample to judge whether the loading sample had an impact on the chromatography by observing the performance of the affinity chromatography column and to evaluate whether the affinity chromatography could achieve the purpose of purifying Pg by detecting the plasma protein antigen concentration and Pg potency of the samples in the process. Two batches of FⅢ-P process were studied step by step, and the specific activity, steps and total recovery, and the output of Pg per ton of plasma were calculated. The feasibility of preparing Pg by FⅢ-P process was evaluated by comparing with the data of full chromatography process using plasma as raw material (hereinafter referred to as plasma process). [Results] The FⅢ-P was dissolved with 10 times of dissolution buffer, stirred for 1 hour, centrifuged at room temperature of 10 000×g for 15 minutes. The supernatant was first filtered with a screen, then clarified with an 8/0.8 μm filter, and finally filtered with a 0.45/0.2 μm filter and loaded. Pre-test showed that from clarification and filtration to Pg affinity chromatography, the step recovery of activity and antigen was 39.51% and 108.64%, respectively, the antigen concentration of Pg increased by 31.16 times and the activity increased by 11.39 times after affinity chromatography, which reaching the effect of affinity chromatography purification of Pg. The results of 2 batches of step-by-step scale-up FⅢ-P process showed that the total recoveries of antigen and activity from plasma to SP chromatography of FⅢ-P process were (45.76±1.10)% and (24.15±0.59)%, respectively, which had a total loss of about 1/3 of antigen and about 2/3 of activity compared to the plasma process. The Pg specific activity of SP chromatography eluent was (4.68±0.25) U/mg, which was about half of that of plasma process, but meeted the internal standard of > 4 U/mg. The output of Pg antigen per ton of plasma in the FⅢ-P process was 68.73% of that in the plasma process, and the output of Pg activity per ton of plasma in the plasma process was 29.82% of that in the plasma process, which basically achieved the purpose of waste utilization of FⅢ-P. [Conclusion] The technical route of preparing Pg from FⅢ-P by full chromatography is feasible.

【Objective】 To determine the ELISA kit for screening convalescence plasma with high potency of SARS-CoV-2 IgG by comparing and analyzing the plasma detection results of convalescent plasma collected in different periods via ELISA kits from two manufacturers and the results of mixed plasma with different potency via pseudovirus neutralization experiments. 【Methods】 Two ELISA kits from different manufacturers(named A, B) were used to detect the plasma of 269 convalescent patients collected from Feb.2020~Jan.2022. The correlation and concordance rate of the two results were analyzed to determine the kit preliminarily. According to the titers of diluted series of standard of the preliminary selected kit, 5 mixed plasma samples (G4-G128) with different potency were prepared. The correlation of ELISA IgG results of product A/B, as well as the pseudovirus neutralization test of the original strain, Omicron mutant BA.1 and BA.2 strains were analyzed. Combined with the outside-well dilution mode of the strongly positive samples, the kit for high potency of SARS-CoV-2 IgG screening was determined. 【Results】 When the internal control reference B2 was used as the standard, the detection sensitivity of product A and B was 1∶32 vs 1∶8; the detection sensitivity of product A was 4 times that of product B. The correlation Pearson r between the results given by two kits was 0.944 1(P<0.000 1). Product B with low sensitivity was primarily selected as an alternative kit. The ELISA IgG results of samples from mixed plasma showed that the order of correlation r between product A and B was 0.988. The correlation r between product A and neutralization antibody potency of the three viruses was original strain (0.978)>BA.2(0.970)>BA.1(0.799); the order of correlation r between ELISA IgG results of product B and neutralization antibody potency of the three viruses was original strain(0.994)>BA.2(0.968)>BA.1(0.804). If twice-diluted B2 was taken as the excellent standard, 55.4% of product B met the criterion, while 47.2% of product A met.For positive plasma with high IgG potency, the product B kit required a lower dilution of the sample, which was more convenient to operate. 【Conclusion】 Both of the ELISA IgG kit from product A and B can be used to screen IgG antibodies of SARS-CoV-2, while product B is more suitable for screening positive plasma with high IgG potency.