Objective To analyze the composition and function of residual cells in pre-transplantation human thymic slices by single-cell transcriptomics sequencing(scRNA-seq),and established a quality assessment method for thymic slices based on the expression levels of molecular markers in the culture supernatant.Methods The discarded thymus from 18 patients with congenital heart disease undergoing surgical treatment in Department of Cardiothoracic Surgery of Children's Hospital Affiliated to Chongqing Medical University from May 2023 to January 2024 were collected and prepared into thymic slices.After the slices were cultured in vitro for 14 d,scRNA-seq was employed to identify the residual cell types,and gene ontology(GO)and Kyoto encyclopedia of genes and genomes(KEGG)enrichment analysis was performed to analyze the biological function of the residual cells.Then based on the literature concerning thymic slice culture,the molecular markers indicating thymocyte function were screened out.ELISA was applied to detect the changes in protein levels of molecular markers in the supernatant.Receiver operating characteristic(ROC)curve was plotted and assess the value of the molecular markers in the supernatant in evaluating the quality of thymic slices with area under the curve(AUC).Then,the qualified and unqualified thymic slices determined by our obtained molecular markers were transplanted subcutaneously into male nude mice(6～8 weeks old,weighing 14～17 g),respectively,and the male nude mice without transplantation of the thymic slices served as control group.Flow cytometry and histologic analysis were utilized to observe the immune reconstitution after transplantation.Results ① scRNA-seq identified 11 cell types in thymic slices,dominated with epithelial cells,fibroblasts,and T cells.GO and KEGG enrichment analysis showed that epithelial cells were involved in enrichment entries related to chemotaxis,epithelial cell development,cell matrix adhesion and tight junction;fibroblasts were involved in enrichment entries related to extracellular matrix,epithelial cell proliferation,negative regulation of cell migration,and regulation of actin cytoskeleton;T cells were mainly related to T cell differentiation,regulation of T cell activation,T cell apoptosis,and T cell receptor signaling.② Molecular markers,CCL19,CCL21,CXCL12,CXCL16,IL16 and SELL were identified to indicate thymocyte function.Compared with the levels of the first day,the protein secretions of CCL19,CCL21,CXCL12 and CXCL16 were significantly increased during in vitro culture(P<0.05),while the protein secretions of IL16 and L-selectin(protein form of SELL)were significantly decreased(P<0.05).The combined predictor Pre1 from subset of cytokines(IL16 and L-selectin)had the highest value in the quality assessment of thymic slices after 1 d of culture(AUC=0.883),and the combined predictor Pre2 from subset of cytokines(CCL19,CCL21,CXCL12 and CXCL16)had the highest value in the quality assessment after 14 d of culture(AUC=0.948).③ Transplantation in nude mice indicated that the qualified thymic slices could develop to thymus structure in vivo,and effectively increase the proportion of T cells in peripheral blood(P<0.01),while the unqualified thymic slices could not obtain the reconstitution of T cell development.Conclusion The main residual component cells in thymic slices are epithelial cells,fibroblasts and T cells.IL16 and L-selectin can be used as potential indicators to determine the quality of donor thymic samples.CCL19,CCL21,CXCL12 and CXCL16 can effectively evaluate the quality of thymic slices before transplantation.

Bone age, the most commonly used and effective indicator for understanding children's growth and development, plays an important role in the diagnosis and efficacy evaluation of various growth and development disorders. Clinically, X-rays of the left hand and wrist are mostly taken for bone age assessment, but there is a certain radiation risk. Ultrasound can clearly display the epiphysis and secondary ossification center, and conveniently perform multi-site scanning and dynamic measurement without radiation. In recent years, great progress has been made in the research and clinical application of ultrasound in bone age assessment. This article, by reviewing the latest literature, discusses the value of musculoskeletal ultrasound and quantitative ultrasound in bone age assessment, raises the problems in the study of ultrasound assessment of bone age, and suggests direction for improvement.

Preliminary exploration of using ultrasound to quantitatively evaluate the development of epiphyseal cartilage and analyze its correlation with bone age, based on the ultrasound findings of the long bone joint end.

To research on area ossification ratio (AOR), a novel parameter for quantitatively assessing adolescent bone age by conventional ultrasonography, and evaluate the correlation between AOR and radiographic bone age.

To evaluate the correlation between ultrasound ossification ratio(OR) and exercise intensity among adolescents.

Objective To explore stress response of government employees,businessmen and police officers.Methods A total of1547 government employees,8672 businessmen and1555 police officers were recruited and completed a questionnaire survey concerning psychological stress.t or F test was used for data analysis.Results There were significant differences of stress response among government employees,businessmen and police officers ( P ＜ 0.01).Male or female government employees showed different stress response,physiology,emotion and behavior (all P＜0.01).Government employees from various age group showed difference in emotion and behavior ( both P ＜ 0.01).Businessmen of various gender and age were found difference of stress response at all dimensions ( P ＜ 0.05 ).Police officers of different gender showed different behavior ( P ＜ 0.0l ).ConclusionIt may be necessary to carry out occupation-specific stress management for individuals.

Objective To study the impacts of quality of life,stress response and sources of stress on mental health of community residents.Methods A total of 703 questionnaires completed by community residents living in Hangzhou and Cangzhou were prospectively collected.All the subjects were assigned o five age groups:18-25 years old group,26-35 years old group,36-50 years old group,51-64 years old group and ≥65 years old group.Psychological health status was compared between the groups by using analysis of variance.Results Significant difference in mental health was found among 5 age groups.Correlation analysis showed that quality of life,stress response and sources of stress had significant effects on mental health.Conclusion Our data suggest significant impacts of quality of life and stress on mental health of community residents.