Objective To study the protective mechanism of dl-3-n butylphthalide (NBP)on oxidative stress injury induced by hydrogen peroxide(H2O2)in rat bone marrow stem cells(rBMSCs).Methods The rBMSCs were divided into control,H2O2 and different concentration NBP pretreatment groups.The control group received no treatment.An oxidative stress injury model was induced by H2O2 for 4 hours with the final concentration 600 μmol/L in the H2O2 group.In the NBP pretreatment groups,the rBMSCs were pretreated with different NBP concentrations(0.1,1,10,and 100 μmol/L)for 24 hours,then treated with H2O2 for 4 hours with the final concentration 600 μmol/L.The cell viability was detected by MTT method.The apoptosis rate was detected by flow cytometry.Superoxide dismutase(SOD)activity and malondialdehyde(MDA)content were measured with SOD and MDA commercial kits.Results The cell activity(A)was 0.487 ±0.018 in the H2O2 group,and it was significantly lower than 0.750 ±0.016 in the control group(P =0.000);they were 0.597 ±0.024,0.666 ±0.033,and 0.658 ±0.012 in the NBP 1,10,and 100 μmol/L pretreatment groups,they were all significantly higher than the H2O2 group(all P =0.000),and showed a dose dependent manner.The apoptosis rate was(44.96 ± 2.84)% in the H2O2 group,and it was significantly higher than (0.15 ±0.07)% in the control group(P= 0.000).The apoptosis rates were(31.79±1.60)% 、(21.41 ± 1.92)% and(22.59 ± 1.78)% in the NBP 1,10,and 100 μmol/L pretreatment groups,they were all significantly lower than the H2O2 groups(all P= 0.000),and showed a dose-dependent manner.The SOD activity was(24.01 ± 2.85)U/mg in the H2O2 group(P = 0.000),and it was significantly lower than(43.58 ± 2.72)U/mg in the control group(P =0.000);they were(28.29 ± 1.19),(34.06 ± 1.83),and(31.76 ± 1.75)U/mg in the NBP 1,10,and 100 μmol/L pretreatment groups,and they were all significantly higher than the H2O2 group(all P = 0.000).The MDA content was(7.98 ± 0.55)nmol/mg in the H2O2 group,and it was significantly higher than(4.73 ± 0.53)nmol/mg in the control group(P =0.000);they were(6.97 ±0.29),6.09 ±0.28),and(6.15 ±0.41)nmol/mg,respectively in the NBP 1,10,and 100 μmol/L pretreatment groups(P = 0.000),they were significantly lower than the H2O2 group,and showed a dose-dependent manner.Conclusions NBP has obvious protective effects on oxidative stress injury induced by H2O2 in rBMSCs.Its mechanism may be associated with the role of antioxidant oxidative stress of NBP.

COVID-19, caused by severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2), can involve in nervous system damage, even severe encephalitis, in addition to respiratory problems. As the number of infections increases, the cases of COVID-19 related encephalitis gradually increase. The mechanism of COVID-19 related encephalitis is still uncertain. Based on relevant literature, we review the possible pathogenesis of COVID-19 related encephalitis and empirical treatment reported in existing cases, hoping to provide theoretical basis for future research and treatment.

Objective:To understand the results of blind evaluation of dissertation of three-year doctors and eight-year medical doctors, and to explore the improvement measures of eight-year program education.Methods:The data analysis method was manipulated. A total of 47 eight-year doctoral and 88 three-year doctoral dissertations submitted by the first clinical college of Huazhong University of Science and Technology in 2020 were selected as the research material. SPSS 17.0 was used to perform Chi-square test to compare the itemized evaluation opinions of the dissertation, Spearman test was used to analyze the correlation between the defense opinions, itemized evaluation opinions and the overall evaluation.Results:The gap between eight-year and three-year doctoral dissertation is mainly manifested in innovation and research value ( χ2=9.10, P=0.003), topic and review ( χ2=5.70, P=0.017), while there is no significant difference in the overall assessment and oral defense suggestion. The main influencing factor of dissertation defense suggestion for both doctors was the dissertation standardization (eight-year: r s=0.53, P<0.001; three-year: r s=0.45, P<0.001). The evaluation results of eight-year doctor dissertation were closely related to basic knowledge and scientific research ability ( r s=0.74, P<0.001). Conclusion:There is no significant difference between eight-year doctors and full-time doctors in research attitude. But there was a certain gap in scientific research and innovation ability among them. It is suggested to clarify the teaching objectives, formulate and refine the evaluation system of dissertations, and strengthen the cultivation of scientific research interest and academic belief of eight-year study program.