Objective: To investigate the extraction,purification,and identification methods of Polygonum cuspidatum(P.cuspidatum)-derived exosomes and to obtain high-purity exosomes,and thus providing a reliable material foundation for their functional studies. Methods: Exosomes were isolated from fresh P.cuspidatum using ultracentrifugation combined with sucrose density gradient centrifugation.Morphological characteristics,size distribution,and surface charge properties were analyzed by transmission electron microscopy(TEM),nanoparticle tracking analysis(NTA),and Zeta potential measurements. Results: The purified P.cuspidatum exosomes exhibited characteristic cup-shaped or spherical bilayer morphology with a predominant size distribution of 100-200 nm,consistent with established plant exosome characteristics.The surface of these exosomes exhibits a negative charge,with the Zeta potential absolute value of root-derived exosomes being slightly higher than that of stem/leaf-derived counterparts. Conclusion The study successfully isolates and characterizes P.cuspidatum exosomes,with comprehensive analysis confirming their distinctive structural and biophysical properties.It lays a good material foundation for further exploration of its active ingredients and biological functions.

Objective To explore the effectiveness of"near peer learning"(NPL)in the electromyo-graphy(EMG)teaching module for neurology residents.Methods The Department of Neurology,Peking Union Medical College Hospital implemented an NPL instructional design for a course on EMG for residents from November 2020 to March 2024.This teaching session was held annually,in which senior residents in-structed juniors who were 1 or 2 years earlier in their training.The residents participated in the pre-course/post-course tests and completed a feedback survey at the end of the session.This evaluation method was used to un-derstand the effectiveness of the NPL intervention in EMG teaching.Results Over four years,a total of 83 residents participated.Among them,there were 24 postdoctoral students,52 postgraduates and 7 junior resi-dents.The results showed that the post-course test scores were significantly improved compared with pre-course test scores(74.33±2.43 vs.70.11±2.49,P=0.005),with the most remarkable improvements seen for"tu-tees"(73.84±20.53 vs.70.29±21.46,P=0.020),postgraduates(74.04±22.51 vs.68.97±21.40,P=0.009),first-year residents(70.19±4.02 vs.63.59±3.59,P=0.040)and first-time participating resi-dents(65.23±3.24 vs.60.97±3.21,P=0.030).The post-program feedback showed that both tutors and tu-tees thought highly of NPL,believing that it enabled them to gain knowledge and helped them to improve teaching skills.Conclusions The NPL intervention is suitable for the teaching of EMG,because of its contri-bution to knowledge acquisition and basic clinical skills improvement.The NPL is worth replicating in other teaching and learning programs.

Objective:To investigate the effect of deubiquitinating enzymes(DUBs) USP2 on depressive-like behavior and hippocampal NF-κB expression in mice.Methods:(1) USP2 silencing experiment: Two USP2 silencing interference sequences with the highest knockdown efficiency were screened and cloned into a lentivirus vector. Mice were microinjected with lentivirus vector into both sides of hippocampus to silence the USP2 gene, and depressive behavior and USP2 protein expression in hippocampal tissue were observed. (2) Venlafaxine intervention experiment: total 32 healthy male C57BL/6 mice were randomly divided into virus control group, Venlafaxine group, USP2 silencing group, and USP2 silencing+ Venlafaxine group according to the random number table method, with 8 mice in each group. Mice were injected with lentivirus into both side of the hippocampus, and 7 days later, they were given intraperitoneal injection of Venlafaxine (5 mg/kg, once a day, for a total of 14 days). After the administration, the depressive behavior of mice was detected by forced swimming test(FST) and tail suspension test(TST), and the expression levels of USP2, p-IκBα, IκBα, p-NF-κB p65, and NF-κB p65 in the hippocampus of mice were detected by Western blot.SPSS 25.0 and GraphPad Prism 8.0 were used for data processing and chart drawing.The t-test was used for comparison between two groups, One-way ANOVA was used for comparison among multiple groups, and Tukey HSD or LSD- t was used for post hoc pairwise comparison when there was homogeneity of variance. Results:(1)The results of the USP2 silencing experiment showed that both screened USP2 silencing sequences had good gene knockout effects. The expression levels of USP2 protein in the hippocampus of mice injected with USP2 silencing virus were lower than those of the negative control virus groups (both P<0.05). The immobility time of mice in the FST and TST was higher than that of the negative control virus group (both P<0.05). (2)Venlafaxine intervention experiment: There were statistically significant differences in immobility time among the four groups of mice in the FST and TST ( F=8.90, 4.41, both P<0.05). The immobility time of FST and the immobility time of TST in the USP2 silencing+ Venlafaxine group ((48.13±12.76) s, (77.38±12.35) s) were lower than those in the USP2 silencing group((129.88±11.67)s, (148.29±15.31)s) (both P<0.05). There were statistically significant differences in the expression levels of USP2, p-IκBα, and p-NF-κB p65 proteins in the hippocampal tissues of the four groups of mice ( F=8.39, 5.78, 21.32, all P<0.05).The expression level of USP2 protein in the USP2 silencing group(0.49±0.07) was lower than that in the USP2 silencing+ Venlafaxine group(0.79±0.08) and virus control group(1.00±0.07)(both P<0.05), while the expression levels of p-IκBα, p-NF-κB p65 protein (1.63±0.18, 2.14±0.24) were higher than those in the virus control group (1.00±0.06, 1.00±0.04) and the USP2 silencing+ Venlafaxine group (0.70±0.23, 0.68±0.09) (both P<0.05). Conclusion:USP2 scilencing can induce depressive-like behaviors in mice. Venlafaxine ameliorates USP2 silencing-induced depressive-like behaviors, which may be associated with the hippocampal NF-κB signaling pathway.

Objective:To investigate the effect of deubiquitinating enzymes(DUBs) USP2 on depressive-like behavior and hippocampal NF-κB expression in mice.Methods:(1) USP2 silencing experiment: Two USP2 silencing interference sequences with the highest knockdown efficiency were screened and cloned into a lentivirus vector. Mice were microinjected with lentivirus vector into both sides of hippocampus to silence the USP2 gene, and depressive behavior and USP2 protein expression in hippocampal tissue were observed. (2) Venlafaxine intervention experiment: total 32 healthy male C57BL/6 mice were randomly divided into virus control group, Venlafaxine group, USP2 silencing group, and USP2 silencing+ Venlafaxine group according to the random number table method, with 8 mice in each group. Mice were injected with lentivirus into both side of the hippocampus, and 7 days later, they were given intraperitoneal injection of Venlafaxine (5 mg/kg, once a day, for a total of 14 days). After the administration, the depressive behavior of mice was detected by forced swimming test(FST) and tail suspension test(TST), and the expression levels of USP2, p-IκBα, IκBα, p-NF-κB p65, and NF-κB p65 in the hippocampus of mice were detected by Western blot.SPSS 25.0 and GraphPad Prism 8.0 were used for data processing and chart drawing.The t-test was used for comparison between two groups, One-way ANOVA was used for comparison among multiple groups, and Tukey HSD or LSD- t was used for post hoc pairwise comparison when there was homogeneity of variance. Results:(1)The results of the USP2 silencing experiment showed that both screened USP2 silencing sequences had good gene knockout effects. The expression levels of USP2 protein in the hippocampus of mice injected with USP2 silencing virus were lower than those of the negative control virus groups (both P<0.05). The immobility time of mice in the FST and TST was higher than that of the negative control virus group (both P<0.05). (2)Venlafaxine intervention experiment: There were statistically significant differences in immobility time among the four groups of mice in the FST and TST ( F=8.90, 4.41, both P<0.05). The immobility time of FST and the immobility time of TST in the USP2 silencing+ Venlafaxine group ((48.13±12.76) s, (77.38±12.35) s) were lower than those in the USP2 silencing group((129.88±11.67)s, (148.29±15.31)s) (both P<0.05). There were statistically significant differences in the expression levels of USP2, p-IκBα, and p-NF-κB p65 proteins in the hippocampal tissues of the four groups of mice ( F=8.39, 5.78, 21.32, all P<0.05).The expression level of USP2 protein in the USP2 silencing group(0.49±0.07) was lower than that in the USP2 silencing+ Venlafaxine group(0.79±0.08) and virus control group(1.00±0.07)(both P<0.05), while the expression levels of p-IκBα, p-NF-κB p65 protein (1.63±0.18, 2.14±0.24) were higher than those in the virus control group (1.00±0.06, 1.00±0.04) and the USP2 silencing+ Venlafaxine group (0.70±0.23, 0.68±0.09) (both P<0.05). Conclusion:USP2 scilencing can induce depressive-like behaviors in mice. Venlafaxine ameliorates USP2 silencing-induced depressive-like behaviors, which may be associated with the hippocampal NF-κB signaling pathway.

Objective:To investigate the alteration of m6A demethylase AlkB homolog 5 (ALKBH5) expression and its impact on form-deprivation myopia (FDM) retina in guinea pigs.Methods:Thirty normal SPF grade 3-week-old tricolor guinea pigs were randomly divided into normal control group and experimental group, with 15 in each group.In the experimental group, the right eyes were covered as FDM group and the left eyes uncovered were set as self-control group.Ocular biometry was performed at one-week intervals from baseline to week 4 of the experiment.Spherical equivalent was detected by streak retinoscopy and axial length was measured by A-scan ultrasonography.Animals were sacrificed after 4 weeks of modeling.The distribution and expression of ALKBH5 protein in the guinea pig retina was detected by immunohistochemical and immunofluorescence staining.Expression of ALKBH5 mRNA and protein in guinea pig retina was detected by real-time fluorescence quantitative PCR and Western blot, respectively.The use of animals in ophthalmic and vision research followed the tenets of Animal Research in Vision and Ophthalmology, and the study was approved by the Ethics Committee of North Sichuan Medical College (No.2023087).Results:At weeks 2, 3, and 4 after myopia induction, diopters and axial lengths were significantly higher in the FDM group than in the normal control group and the self-control group (all at P<0.001). Immunohistochemistry and immunofluorescence assays showed that ALKBH5 protein was expressed in the retinal nerve fiber layer, rod/cone photoreceptor cells, and retinal pigment epithelium (RPE) layer, and was highly expressed in the retinal nerve fiber layer and RPE layer.The relative ALKBH5 immunofluorescence intensity in the normal control group, self-control group and FDM group was 1.000±0.204, 0.874±0.076 and 0.571±0.053, respectively, which was lower in the FDM group than in the normal control and self-control groups, showing statistically significant differences ( t=4.069, P=0.006; t=5.176, P=0.014). After 4 weeks of modeling, ALKBH5 mRNA and protein expressions were significantly lower in FDM group than in normal control and self-control groups (both at P<0.01). Conclusions:The expression of m6A demethylase ALKBH5 is decreased in the retina of FDM guinea pigs, suggesting that ALKBH5 and related m6A methylation modification may be involved in the development and progression of myopia.

Objective: To examine the association between sleep and frailty using the bidirectional two-sample Mendelian randomization (MR) approach, so as to provide the basis for the prevention and intervention of frailty. Methods: The data on single nucleotide polymorphisms (SNP) related to sleep duration, insomnia and morning chronotype were collected from genome-wide association studies (GWAS) and meta-analysis of GWAS, involving 446 118, 1 331 010 and 697 828 participants, respectively. The frailty was evaluated using the frailty index, and the relevant SNP data were collected from a meta-analysis of GWAS involving 175 226 participants. A bidirectional MR analysis was performed using the inverse-variance weighted method. Sensitivity analyses employed the weighted median method, the maximum likelihood-based method, the MR-Egger regression, and the MR-PRESSO test. Results: Forward MR analysis showed that longer sleep duration (β=-0.170, 95%CI: -0.255 to -0.085) and morning chronotype (β=-0.036, 95%CI: -0.058 to -0.014) decreased the risk of frailty, while insomnia increased the risk of frailty (β=0.167, 95%CI: 0.149-0.184). Reverse MR analysis showed that frailty increased the risk of insomnia (OR=1.645, 95%CI: 1.278-2.117). Both bidirectional MR results were robust, which excluded the impact of heterogeneity and horizontal pleiotropy. Conclusion Sleep duration, insomnia, and morning chronotype are associated with frailty.

To explore the effectiveness of "near peer learning" (NPL) in the electromyography(EMG)teaching module for neurology residents.

OBJECTIVE To analyze the effects of the national centralized drug procurement （NCDP） policy on drug availability and the structure of drug use in public hospitals. METHODS Using hypoglycemic， lipid-lowering， antiviral drugs， and psychiatric drugs for the treatment of mental illness and depression as objects， the interrupted time series model was used to quantitatively evaluate the changes in consumption sum of drugs， consumption amount and daily cost of the target drugs in national sample hospitals as well as the changes in per capita medication frequency， outpatient prescription amount， and medical insurance surplus of target drugs in a third grade class A hospital before and after the implementation of NCDP policy. RESULTS After the implementation of the NCDP policy， the volume for the four bid-winning drugs increased significantly （P＜0.01 for the remaining three categories except for hypoglycemic drugs）， but DDDc （P＜0.01） and the amount of related drugs （P＜0.001） decreased significantly. The volume for the non-winning drugs （except for lipid-lowering drugs） decreased significantly （P＜0.05）， and DDDc also decreased significantly （P＜0.05 for other 3 categories except for psychiatric drugs）； the volume （P＜0.01） and DDDc （P＜0.01 only for psychiatric drugs） for alternative drugs all increased except for antiviral drugs. The structure of drug use for different drugs was affected differently by the NCDP policy，and that of hypoglycemic drugs was affected obviously； the proportion of alternative drugs increased after centralized procurement. The outpatient prescription amount of each hospital significantly decreased after centralized procurement，and the decrease in the cost paid by the patients using lipid-lowering and antiviral drugs related to centralized procurement was greater than 0.60； the remaining medical insurance amount for bid-winning drugs was approximately 1.252 5 million yuan. CONCLUSIONS NCDP policy effectively alleviates the burden of medical expenditure and also drives the structure changes of drug use such as the substitution of generic drugs for original drugs， the growth of the volume of alternative drugs.

Objective:To investigate the mechanism of depression between social capital and cognitive function of the elderly in nursing institutions, and provide new ideas for improving the cognitive function of the elderly.Methods:This study was a cross-sectional survey. Using the convenient sampling method to collect the general information questionnaire, the Geriatric Depression Scale (GDS), Social Capital Scale and Montreal Cognitive Assessment Scale (MoCA) of 218 elderly people from three elderly nursing institutions including Shenyang Health Care Centre, Songpu Nursing Home and Colourful Sunshine City Pension Service Centre in Shenyang from July 2020 to January 2021.Results:A total of 218 questionnaires were distributed and 202 valid questionnaires were recovered. The effective recovery rate was 92.7%. The scores of the cognitive function, depression and social capital of the elderly were (23.60 ± 4.25), (6.38 ± 4.35) and (75.41 ± 8.61). Depression scores were negatively correlated with social capital scores and cognitive function scores ( r = - 0.401, - 0.481, both P<0.05); there was a positive correlation between social capital scores with cognitive function scores ( r = 0.338, P<0.05). There was a mediating effect of depression between social capital and cognitive function, accounting for 42.1%. Conclusions:While improving the cognitive function of the elderly in nursing institutions by improving the level of social capital, it is necessary to pay attention to the mediatingeffect of depression, strengthen the psychological counseling of the elderly, promote mental health, and further reduce the occurrence and development of cognitive decline in the elderly.

Objective:To analyze the clinical epidemiological characteristics and the prognostic risk factors of patients with hemorrhagic fever with renal syndrome (HFRS).Methods:A total of 2 245 HFRS patients who were admitted to the Second Affiliated Hospital of Air Force Medical University from September 2008 to December 2021 were enrolled. Clinical epidemiological data (including gender, age, onset season, onset region, case fatality rate, et al) of HFRS patients were analyzed. The clinical epidemiological characteristics of patients with HFRS in the 2008 to 2012, 2013 to 2017, and 2018 to 2021 groups were compared. Statistical comparisons were performed using chi-square test. The Bonferroni adjusted P-value method was used for pairwise comparisons between groups, and logistic regression analysis was used to screen and evaluate the risk factors associated with the prognosis of HFRS patients. Results:The age of 2 245 HFRS patients was (42.3±15.9) years old. Most of them were male (79.24%(1 779/2 245)), and the main incidence area was Xi′an City (69.53%(1 561/2 245)). There were 132 deaths with an overall case fatality rate of 5.88%. There were 1 088 patients (48.46%) from 2008 to 2012, 647 patients (28.82%) from 2013 to 2017, and 510 patients (22.72%) from 2018 to 2021, with a mortality rate of 7.17%(78/1 088), 5.10%(33/647) and 4.12%(21/510), respectively. From 2008 to 2021, both the number of HFRS cases and the case fatality rate had shown a fluctuating downward trend. There were significant differences in case fatality rate, age distribution, onset season, and onset region among patients in the different year groups ( χ2=6.84, 49.22, 83.47 and 19.29, respectively, all P<0.05). The results of pairwise comparisons showed that the proportion of patients aged >60 years in the 2018 to 2021 group (23.33%(119/510)) was higher than those in the 2008 to 2012 group (12.13%(132/1 088)) and the 2013 to 2017 group (12.36%(80/647)), and the differences were statistically significant (both P<0.05). The proportions of patients at large peak (October to December) were 62.35%(318/510) in the 2018 to 2021 group and 56.26%(364/647) in the 2013 to 2017 group, which were both lower than that in the 2008 to 2012 group (75.18%(818/1 088)), and the differences were both statistically significant (both P<0.05). The case fatality rate of patients aged >60 years was 9.67%(32/331), which was higher than those of patients aged <30 years (2.86%(16/559)) and patients aged 30 to 60 years (6.20%(84/1 355)), with statistically significant differences (both P<0.05). Univariate analysis showed that age 30 to 60 years, age >60 years, smoking, complicated with hypertension, hypotensive shock and hypoxemia were significantly correlated with the prognosis of HFRS patients (odds ratio ( OR)=2.243, 3.632, 1.484, 3.532, 79.422 and 143.955, respectively, all P<0.05). The results of multivariate logistic regression analysis indicated that complicated with hypertension ( OR=2.467, P=0.004), hypotensive shock ( OR=11.658, P=0.001), and hypoxemia ( OR=67.767, P<0.001) were the independent risk factors affecting the prognosis of HFRS patients. Conclusions:The prevalence of HFRS has shown new changing characteristics from 2008 to 2021. The numbers of HFRS patients and the case fatality rates show a downward trend, and the proportion of HFRS patients aged >60 years increases. Complicated with hypertension, hypotensive shock and development with hypoxemia are the independent risk factors for the prognosis of HFRS.