Objective:To prepare the bacterial outer membrane vesicles(OMV)that can express programmed death ligand 1(PD-L1)nanobody on surface,and to discuss its structural characteristics,cell compatibility,intracellular distribution,and its blocking effect on the programmed cell death protein-1(PD-1)/PD-L1 signaling axis.Methods:The pET28a-ClyA-PD-L1nb prokaryotic expression vector was constructed and transformed into Escherichia coli BL21(DE3)competent cells;the OMV was isolated from the BL21(DE3)monoclonal colonies transformed with the PD-L1nb expression vector by ultracentrifugation;the protein purification was performed using the histidine(His)tag;transmission electron microscope and nanoparticle size analyzer were used to analyze and identify the OMV;the OMV isolated from the BL21(DE3)monoclonal colonies transformed with the PD-L1nb expression vector was used as experimental group;the OMV isolated from the untransformed BL21(DE3)monoclonal colonies was used as control group;Western blotting method was used to detect the expression levels of ClyA-PD-L1nb fusion protein in the OMV in two groups;cell counting kit-8(CCK-8)assay was used to detect the activities of mouse macrophage RAW 264.7 cells,mouse triple-negative breast cancer 4T1 cells,and human embryonic kidney HEK293T cells after treated with OMV;fluorescence imaging technology was used to observe the tumor cell endocytosis of OMV;flow cytometry was used to detect the binding effect of OMV to the PD-L1 on surface of the tumor cells in PBS group,OMV-PD-L1nb group,and aPD-L1+OMV-PD-L1nb group.Results:The sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE)results showed that after induction of Escherichia coli,significantly thickened protein bands appeared near the predicted relative molecular mass(about 49 000),and after purification,no obvious impurity proteins existed in the lanes;the OMV-PD-L1nb with a size of about 120 nm was isolated by ultracentrifugation,and it presented a uniform spherical structure under transmission electron microscope;the Western blotting results showed that the specific band of ClyA-PD-L1nb was detected in the OMV in experimental group;the CCK-8 assay results showed that after treated with different concentrations of OMV,the viabilities of the RAW 264.7 cells,4T1 cells,and HEK293T cells were all close to 100％;the fluorescence imaging results showed that OMV-PD-L1nb was endocytosed by 4T1 cells and dispersed in the cytoplasm;compared with OMV-PD-L1nb group,the average fluorescence intensity in the cells in aPD-L1+OMV-PD-L1nb group was significantly decreased(P＜0.001).Conclusion:The OMV surface-displaying PD-L1nb,OMV-PD-L1nb,is successfully prepared and isolated;OMV-PD-L1nb shows good compatibility on mouse macrophage cells,tumor cells,and human embryonic kidney cells,can be endocytosed by tumor cells,and successfully blocks the PD-1/PD-L1 signaling pathway.

Objective To explore the perioperative therapeutic effects and follow-up manage-ment in 16 patients with left ventricular assist device(LVAD)implantation.Methods A retrospec-tive analysis was conducted in data of 16 patients who underwent LVAD implantation in the depart-ment of cardiovascular surgery.Data of 6-minute walk test(6MWT),European Quality of Life-5 Di-mension-5 Levels(EQ-5D-5L),New York Heart Association(NYHA)classification,echocardio-graphy,chest radiography,cardiothoracic ratio,and occurrence of complications(infection,bleed-ing,thrombosis,right heart failure,neurological issues)were collected via the electronic medical re-cord system before surgery and at 30,60,and 90 days postoperatively.Results All patients sur-vived with the pump at 90 days postoperatively.One patient with preoperative renal insufficiency un-derwent dialysis and received a heart transplant after 8 months.One patient developed a sterile granu-loma at the percutaneous lead site on the abdominal wall,which improved after treatment,no complica-tions occurred in other patients.At 90 days postoperatively,there was no statistically significant differ-ence in the right ventricular area change fraction and tricuspid annular plane systolic excursion com-pared with preoperative values(P＞0.05).The left ventricular ejection fraction,left ventricular end-diastolic diameter,and cardiothoracic ratio showed significant improvement compared with preoperative levels(P＜0.05).At 30 days postoperatively,30％of patients recovered to NYHA class Ⅰ and 70％to class Ⅱ;at 60 days,80％of patients to class Ⅰ and 20％to class Ⅱ;at 90 days,90％to classⅠ and 10％to class Ⅱ.The 6MWT and EQ-5D-5L scores of patients significantly increased within 90 days postoperatively(P＜0.01).Conclusion Through rigorous preoperative assessment by a multidisciplinary LVAD team,refinement of surgical techniques,and comprehensive management during hospitalization,self-management before discharge,daily follow-up after discharge,and fol-low-up management upon returning to the hospital for patients with LVAD implantation,the cardiac function and quality of life of patients are significantly improved at 90 days postoperatively.

Objective:To explore the relationship between school bullying and mental sub-health in middle school students and the potential moderating role of resilience in this relationship.Methods:Totally 792 students aged 10 to 14 years from two middle schools in Wuhan were selected.The Chinese version of Olweus Bully/Victim Questionnaire,Multidimensional Sub-health Questionnaire of Adolescents,and Adolescent Psychological Resilience Scale were used to measure school bullying,mental sub-health,and psychological resilience of students,respectively.Results:Being bullied scores were positively associated with mental sub-health scores(β=1.88).The moderating effect of psychological resilience scores between being the scores of bullied and mental sub-health was statistically significant(β=-0.07).Conclusion:The experience of bullying may be associated with mental sub-health problems of middle school students,and psychological resilience may play a moderating role in the relation-ship between being bullied and mental sub-health.

Objective To investigate the plasma level of interleukin-31(IL-31)in patients with pulmonary arterial hypertension(PAH)and its clinical relevance.Methods The patients who were diagnosed as PAH in Zhongshan Hospital,Fudan University from January 1,2021 to December 30,2023(PAH group)and the healthy people in the same period(control group)were selected.The clinical data and follow-up records were collected.Plasma levels of IL-31,IL-1β,IL-6,IL-10,IL-12p70,monocyte chemoattractant protein-1(MCP-1),tumor necrosis factor-α(TNF-α)and transforming growth factor-β1(TGF-β1)were detected by enzyme-linked immunosorbent assay(ELISA).Pearson correlation test was used to evaluate the correlations between IL-31 and right cardiac catheterization parameters,echocardiography parameters and blood indices in patients with PAH.Cox proportional hazard model was used to analyze the prognostic factors of patients in PAH group.Results A total of 50 patients with PAH and 22 healthy controls were included.There was no significant difference in age,gender,body mass index and left ventricular ejection fraction between the two groups.Compared with the control group,the plasma level of IL-31 in the PAH group was significantly higher(168.82[149.14,177.26]pg/mL vs 152.76[145.58,159.41]pg/mL,P=0.001).Pearson correlation test showed that the plasma level of IL-31 in PAH patient was positively correlated with mean pulmonary artery pressure(r=0.652,P＜0.001)and pulmonary vascular resistance(r=0.651,P＜0.001),but was negatively correlated with tricuspid annular plane systolic excursion(r=-0.496,P＜0.001).Cox proportional hazard model showed that higher plasma level of IL-31 was an independent predictor of readmission for heart failure/all-cause mortality in patients with PAH(HR=1.130,95％CI 1.052-1.214,P=0.001).Conclusions Plasma level of IL-31 may be significantly increased in patients with PAH and be positively correlated with the severity of PAH,and elevated level of IL-31 is predictive of poor prognosis in PAH patients.

Purpose To study the changes of topological properties of brain structure network in age-related hearing loss(ARHL)by using graph theory,and to explore the relationship between the changes of brain structure network and cognition.Materials and Methods A total of 31 patients with ARHL and 27 controls from October 2022 to October 2023 in People's Hospital of Anshun City were recruited to undergo a diffusion tensor imaging scan and cognitive tests.Based on graph theory,this paper analyzes the changes of topological attributes of brain networks.The global attributes included small-world attribute,clustering coefficient,characteristic path length,global efficiency,local efficiency and network compatibility.The local attributes included nodal clustering coefficient,nodal shortest length,node efficiency,nodal local efficiency,nodal degree centrality and nodal betweenness centrality.And the correlation between abnormal brain network topology and cognition were explored.Results Compared with the control group,the characteristic path length in ARHL group significantly increased,and the global efficiency and local efficiency significantly decreased(t=3.08,-3.15,-3.30;all P<0.01);the nodal shortest length of the right orbital inferior frontal gyrus increases,while the node efficiency of the left dorsolateral superior frontal gyrus,bilateral orbital inferior frontal gyrus and left medial superior frontal gyrus decreases,and the nodal degree centrality of the left dorsolateral superior frontal gyrus,left superior parietal gyrus and left precuneus decreases(t=-4.74-5.19;all P<0.001).The Montreal cognitive assessment score in ARHL group was negatively correlated with the characteristic path length(r=-0.390,P=0.030),and positively correlated with the global efficiency(r=0.390,P=0.030)and the nodal degree centrality value of left precuneus(r=0.466,P=0.008).The mini-mental state examination score was negatively correlated with the characteristic path length(r=-0.473,P=0.007),and with the global efficiency(r=0.473,P=0.007),local efficiency(r=0.408,P=0.023),and the nodal degree centrality value of left precuneus(r=0.363,P=0.363).Conclusion There are abnormalities in the topological properties of the brain network in ARHL,and the abnormal brain regions are mainly distributed in the prefrontal and parietal lobe,among which the abnormal changes in the left precuneus may play a key role in cognitive dysfunction.

Objective:To evaluate the performance of an artificial intelligent (AI)-based automated digital cell morphology analyzer (hereinafter referred as AI morphology analyzer) in detecting peripheral white blood cells (WBCs).Methods:A multi-center study. 1. A total of 3010 venous blood samples were collected from 11 tertiary hospitals nationwide, and 14 types of WBCs were analyzed with the AI morphology analyzers. The pre-classification results were compared with the post-classification results reviewed by senior morphological experts in evaluate the accuracy, sensitivity, specificity, and agreement of the AI morphology analyzers on the WBC pre-classification. 2. 400 blood samples (no less than 50% of the samples with abnormal WBCs after pre-classification and manual review) were selected from 3 010 samples, and the morphologists conducted manual microscopic examinations to differentiate different types of WBCs. The correlation between the post-classification and the manual microscopic examination results was analyzed. 3. Blood samples of patients diagnosed with lymphoma, acute lymphoblastic leukemia, acute myeloid leukemia, myelodysplastic syndrome, or myeloproliferative neoplasms were selected from the 3 010 blood samples. The performance of the AI morphology analyzers in these five hematological malignancies was evaluated by comparing the pre-classification and post-classification results. Cohen′s kappa test was used to analyze the consistency of WBC pre-classification and expert audit results, and Passing-Bablock regression analysis was used for comparison test, and accuracy, sensitivity, specificity, and agreement were calculated according to the formula.Results:1. AI morphology analyzers can pre-classify 14 types of WBCs and nucleated red blood cells. Compared with the post-classification results reviewed by senior morphological experts, the pre-classification accuracy of total WBCs reached 97.97%, of which the pre-classification accuracies of normal WBCs and abnormal WBCs were more than 96% and 87%, respectively. 2. The post-classification results reviewed by senior morphological experts correlated well with the manual differential results for all types of WBCs and nucleated red blood cells (neutrophils, lymphocytes, monocytes, eosinophils, basophils, immature granulocytes, blast cells, nucleated erythrocytes and malignant cells r>0.90 respectively, reactive lymphocytes r=0.85). With reference, the positive smear of abnormal cell types defined by The International Consensus Group for Hematology, the AI morphology analyzer has the similar screening ability for abnormal WBC samples as the manual microscopic examination. 3. For the blood samples with malignant hematologic diseases, the AI morphology analyzers showed accuracies higher than 84% on blast cells pre-classification, and the sensitivities were higher than 94%. In acute myeloid leukemia, the sensitivity of abnormal promyelocytes pre-classification exceeded 95%. Conclusion:The AI morphology analyzer showed high pre-classification accuracies and sensitivities on all types of leukocytes in peripheral blood when comparing with the post-classification results reviewed by experts. The post-classification results also showed a good correlation with the manual differential results. The AI morphology analyzer provides an efficient adjunctive white blood cell detection method for screening malignant hematological diseases.

Objective:To compare the self-evaluated learning behavior and achievement of eight-year-program clinical medical students on online and offline problem-based learning (PBL), and to provide references and suggestions for successful implementation of online PBL teaching.Methods:During the three semesters of September 2020 to January 2022, a survey was performed on 100 clinical medical students of 2018 eight-year program on online or offline PBL teaching in Xiangya School of Medicine, Central South University. At the end of PBL courses, the students received questionnaires to self-assess their learning behavior and achievement in online or offline PBL teaching. The data were analyzed using the paired rank sum test with the use of SPSS 26.0.Results:Before class, there were no significant differences in learning behaviors including preparation time, communication with classmates, and materials collecting and sorting between students on online and offline PBL teaching ( P>0.05). In class, no significant differences were found in students' initiative of speaking and degree of satisfaction with classmates' speaking between online and offline teaching ( P>0.05), but the students on offline teaching showed significantly better concentration of attention ( Z=-4.24, P<0.001), listening to classmates' speeches ( Z=-3.42, P=0.001), and classmates' interaction ( Z=-3.11, P=0.002) compared with those on online teaching. No significant differences were observed between online and offline PBL teaching in students' self-evaluated learning achievements including improvements in autonomous learning ability, problem-solving ability, and literature inquiry skills ( P>0.05). Conclusion:Students on online PBL teaching have generally as good pre-class preparation and in-class learning performance as those on offline PBL teaching, indicating that the online PBL mode can be well implemented, and it can also ensure almost the same learning achievement as offline teaching.

Bisecting N-acetylglucosamine(GlcNAc),a GlcNAc linked to the core β-mannose resi-due via a β1,4 linkage,is a special type of N-glycosylation that has been reported to be involved in various biological processes,such as cell adhesion and fetal development.This N-glycan structure is abundant in human trophoblasts,which is postulated to be resistant to natural killer cell-mediated cytotoxicity,enabling a mother to nourish a fetus without rejection.In this study,we hypothesized that the human amniotic membrane,which serves as the last barrier for the fetus,may also express bisected-type glycans.To test this hypothesis,glycomic analysis of the human amniotic membrane was performed,and bisected N-glycans were detected.Furthermore,our pro-teomic data,which have been previously employed to explore human missing proteins,were ana-lyzed and the presence of bisecting GlcNAc-modified peptides was confirmed.A total of 41 glycoproteins with 43 glycopeptides were found to possess a bisecting GlcNAc,and 25 of these gly-coproteins were reported to exhibit this type of modification for the first time.These results provide insights into the potential roles of bisecting GlcNAc modification in the human amniotic membrane,and can be beneficial to functional studies on glycoproteins with bisecting GlcNAc modifications and functional studies on immune suppression in human placenta.

Abstract The outbreak of tuberculosis in campus shows a profound impact on academic learning and mental health of students, which might result in more serious social problems. The present editorial addresses weak links in the school tuberculosis prevention and control. Disease prevention and control institutions, medical institutions, education administrative departments and schools need to clarify work responsibilities, strictly implement the school tuberculosis prevention and control laws, regulations and management guidelines, and coordinate with multiple departments, with the aim to strengthen early warning capacity for campus tuberculosis, improve tuberculosis screening and risk assessment of relevant personnel, and implement the health checkup of schools and faculty, as well as the screening, diagnosis, registration, treatment and follow up of students cases. To further improve tuberculosis control across China, strengthening the awareness of tuberculosis prevention and control among institutions and the public, and improving adherence to tuberculosis treatment, as well as moving forward from passive to active tuberculosis monitoring and early prevention, reducing the occurrence of tuberculosis outbreak in school should be prioritized, so as to promote the smooth development of tuberculosis prevention and control work in China.

Mild cognitive impairment (MCI) is a pre-clinical stage of Alzheimer's disease (AD). In recent years, transcranial direct current stimulation (tDCS), as a neuromodulation technique, has being applied in the field of cognitive intervention for MCI, but its effect is controversial because of many factors. In order to promote the application of tDCS in intervention for MCI, this study performed a systematic review of the previous studies that used tDCS to improve cognitive functions of MCI individuals. The results indicate that tDCS could improve episodic memory, working memory, and language of individuals with MCI, while there is a lack of strong evidence that supports a positive effect of tDCS on attention of individuals with MCI. The placement of electrodes, time course of treatment, and current intensity all affected the intervention effect of tDCS. Future studies should take brain networks underlying cognitive processes and personalized factors such as age and education level into consideration to design better stimulation protocols, and they should be conducted in combination with neuroimaging technologies to evaluate the intervention effect of tDCS more accurately and objectively and to discover the neural mechanisms of tDCS intervention.