Objective: To explore the relationship between visual acuity and physical fitness of university freshmen, so as to provide reference for myopia prevention and control for freshmen. Methods: From October to November 2022, 2 160 college freshman without majoring in public safety administration, selected from Guangxi Police College in 2022 by using the stratified cluster random sampling method, were reviewed for the results of visual acuity test and physical fitness scores. The physical fitness indices were evaluated by using the Z scores of physical fitness test scores, and the strength of association between the level of physical fitness index and myopia was analyzed by using Logistic regression model. Results: Among 2 160 college freshman without majoring in public safety administration, 917 (42.5%) students were diagnosed screening myopia, including 66 (3.1%) cases of high myopia, 383 (17.7%) cases of moderate myopia and 468 (21.7%) cases of mild myopia. The differences in the distribution of visual acuity tests among students with different physical fitness indices, body mass index, and gender were statistically significant ( Z/H=54.50, 49.53, 15.51, P <0.01). Low level and low middle level physical fitness indices were associated with screening myopia among freshmen[ OR (95% CI )=2.81(1.93-4.08),1.87(1.38-2.54)], and low level physical fitness indexes were associated with high myopia [ OR (95% CI )=7.22(2.33-22.32)] ( P <0.01). Conclusions Screening myopia among college freshman without majoring in public safety administration is related to physical fitness, and low level and low middle level physical fitness index are risk factors for myopia. Improving the level of physical fitness might be effective in preventing myopia.

ObjectiveThis study leverages structural data from antigen-antibody complexes of the influenza A virus neuraminidase (NA) protein to investigate the spatial recognition relationship between the antigenic epitopes and antibody paratopes. MethodsStructural data on NA protein antigen-antibody complexes were comprehensively collected from the SAbDab database, and processed to obtain the amino acid sequences and spatial distribution information on antigenic epitopes and corresponding antibody paratopes. Statistical analysis was conducted on the antibody sequences, frequency of use of genes, amino acid preferences, and the lengths of complementarity determining regions (CDR). Epitope hotspots for antibody binding were analyzed, and the spatial structural similarity of antibody paratopes was calculated and subjected to clustering, which allowed for a comprehensively exploration of the spatial recognition relationship between antigenic epitopes and antibodies. The specificity of antibodies targeting different antigenic epitope clusters was further validated through bio-layer interferometry (BLI) experiments. ResultsThe collected data revealed that the antigen-antibody complex structure data of influenza A virus NA protein in SAbDab database were mainly from H3N2, H7N9 and H1N1 subtypes. The hotspot regions of antigen epitopes were primarily located around the catalytic active site. The antibodies used for structural analysis were primarily derived from human and murine sources. Among murine antibodies, the most frequently used V-J gene combination was IGHV1-12*01/IGHJ2*01, while for human antibodies, the most common combination was IGHV1-69*01/IGHJ6*01. There were significant differences in the lengths and usage preferences of heavy chain CDR amino acids between antibodies that bind within the catalytic active site and those that bind to regions outside the catalytic active site. The results revealed that structurally similar antibodies could recognize the same epitopes, indicating a specific spatial recognition between antibody and antigen epitopes. Structural overlap in the binding regions was observed for antibodies with similar paratope structures, and the competitive binding of these antibodies to the epitope was confirmed through BLI experiments. ConclusionThe antigen epitopes of NA protein mainly ditributed around the catalytic active site and its surrounding loops. Spatial complementarity and electrostatic interactions play crucial roles in the recognition and binding of antibodies to antigenic epitopes in the catalytic region. There existed a spatial recognition relationship between antigens and antibodies that was independent of the uniqueness of antibody sequences, which means that antibodies with different sequences could potentially form similar local spatial structures and recognize the same epitopes.

Nonobstructive azoospermia (NOA), one of the most severe types of male infertility, etiology often remains unclear in most cases. Therefore, this study aimed to detect four biallelic detrimental variants (0.5%) in the minichromosome maintenance domain containing 2 ( MCMDC2 ) genes in 768 NOA patients by whole-exome sequencing (WES). Hematoxylin and eosin (H&E) demonstrated that MCMDC2 deleterious variants caused meiotic arrest in three patients (c.1360G>T, c.1956G>T, and c.685C>T) and hypospermatogenesis in one patient (c.94G>T), as further confirmed through immunofluorescence (IF) staining. The single-cell RNA sequencing data indicated that MCMDC2 was substantially expressed during spermatogenesis. The variants were confirmed as deleterious and responsible for patient infertility through bioinformatics and in vitro experimental analyses. The results revealed four MCMDC2 variants related to NOA, which contributes to the current perception of the function of MCMDC2 in male fertility and presents new perspectives on the genetic etiology of NOA.
Humans ; Male ; Azoospermia/genetics* ; Meiosis/genetics* ; Spermatogenesis/genetics* ; Adult ; Exome Sequencing ; Microtubule-Associated Proteins/genetics* ; Alleles ; Infertility, Male/genetics*

OBJECTIVES: To study the impact of family socioeconomic status on children's reading fluency and the chain mediation effect of family reading environment and children's living and learning styles in this relationship. METHODS: A total of 473 children from grades 2 to 6 in two primary schools in Nanjing were selected through stratified random sampling. The children's reading fluency was assessed, and a questionnaire was used to collect information on family socioeconomic status, family reading environment, and children's living and learning styles. The mediation model was established using the Process macro in SPSS, and the Bootstrap method was employed to test the significance of the mediation effects. RESULTS: Family socioeconomic status, family reading environment, and children's living and learning styles were significantly positively correlated with reading fluency (P<0.001). The family reading environment and children's living and learning styles mediated the relationship between family socioeconomic status and children's reading fluency. Specifically, the independent mediation effect of family reading environment accounted for 11.02% of the total effect, while the independent mediation effect of children's living and learning styles accounted for 10.79%. The chain mediation effect of family reading environment and children's living and learning styles accounted for 7.41% of the total effect. CONCLUSIONS Family socioeconomic status can affect children's reading fluency through three pathways: family reading environment, children's living and learning styles, and the chain mediation effect of family reading environment and children's living and learning styles.
Humans ; Child ; Male ; Female ; Reading ; Learning ; Social Class ; Family

Background: Intradermal microdroplet injections of botulinum toxin type-A (BoNT/A) effectively ameliorate rosacea-related angiogenesis, but the mechanism remains unclear. Objective: To explore the anti-angiogenesis of BoNT/A in the rosacea-like mouse model and to measure the secretion of vascular endothelial growth factor (VEGF) by mast cells. Methods: A rosacea-like mouse model was induced by LL37 in both Mas-related G-proteincoupled receptor B2 conditional knockout (MrgprB2 −/− ) mice and wild-type (WT) mice, then treated with BoNT/A and/or Apatinib. The abundance of endothelial cells and mast cells in mouse skin was determined using dual immunofluorescence staining. The VEGF levels in supernatants and cell lysates of laboratory of allergic disease 2 (LAD2) mast cells were assessed using reverse transcription quantitative polymerase chain reaction, western blots, and enzyme-linked immunosorbent assay. The effect of conditioned medium (CM) collected from LAD2 on human umbilical vein endothelial cells (HUVECs) was determined using tube formation assays. The number of proliferative cells was confirmed using the 5-ethynyl-2’-deoxyuridine incorporation assays.The effect of BoNT/A on the internalization of Mas-related G-protein-coupled receptor X2 (MRGPRX2) was detected using flow cytometry and immunofluorescence staining. Results: LL37-induced rosacea-like skin manifestations were significantly alleviated in MrgprB2 −/− mice compared to WT controls. BoNT/A mitigated the LL37-induced secretion of VEGF by LAD2. The CM from BoNT/A-treated LAD2 inhibited HUVEC proliferation and tube formation. The LAD2 cells co-treated with LL37 and BoNT/A exhibited dramatically enhanced MRGPRX2 internalization. Conclusion BoNT/A enhances LL37-mediated MRGPRX2 internalization in mast cells, thereby reducing VEGF secretion and neovascularization and improving facial flushing symptom in rosacea.

Objective To analyze the results of ultrasonic examinations of hip joints in preterm infants,clarify the developmental characteristics of hip joints across different gestational ages.Meth-ods A total of 881 preterm infants who attended the Child Healthcare Outpatient Clinic of Nanjing Maternity and Child Health Care Hospital between January 2023 and April 2024 were enrolled.The first ultrasonic examination of the hip joints was performed at a corrected gestational age of 4 to 6 weeks.The Graf classification method was employed to categorize the ultrasonic findings.Differences in hip joint development among preterm infants of varying gestational ages were compared,and rele-vant influencing factors were statistically analyzed.Results A total of 1,762 hip joints were exam-ined,with 30 cases of abnormal hip joints detected,yielding an abnormality detection rate of 3.4％(30/881).Among these,26 hips were classified as type Ⅱa and 8 as type Ⅱb.Statistically signifi-cant differences were observed in the detection of left-sided abnormal hip joints between preterm in-fants of other gestational age groups and late preterm infants(P＜0.05).A statistically significant difference was found in the classification of right-sided hip joints between preterm infants of different genders(P＜0.05),while no significant difference was observed for left-sided hip joints(P＞0.05).Statistically significant differences were noted in the detection rates of bilateral abnormal hip joints among preterm infants with varying birth weights(P＜0.05).Advanced maternal age was found to influence the development of left-sided hip joints inpreterm infants,whereas factors such as assisted reproductive technology,breech presentation,and nulliparity had no significant impacts on abnormal hip joint development in preterm infants.Conclusion Ultrasonic technology demonstrates signifi-cant advantages in screening for developmental dysplasia of the hip(DDH)in preterm infants.Dif-ferent gestational ages exert a notable influence on the development of left-sided hip joints in preterm infants.Female preterm infants exhibit a higher risk of right-sided hip joint abnormalities compared to the left side.Breech presentation,assisted reproductive technology,and nulliparity are not risk factors for DDH in preterm infants.However,higher birth weight in preterm infants and advanced maternal age are associated with abnormal hip joint development.Clinical attention should focus on high-risk factors,and enhanced dynamic ultrasonic monitoring of hip joints in preterm infants is war-ranted to facilitate early intervention and treatment.

Objective To explore an assessment model for multi-level integrated training in health service based on advanced intelligent trauma simulators in order to innovate health service training.Methods An assessment model for multi-level integrated training that involved advanced trauma simulators was adopted to assess chains of treatment and rescue that were composed of multi-hierarchy medical institutions.The assessment focused on trauma emergency response capabilities at each level and the overall therapeutic effect.Results In terms of capabilities for treatment and rescue,group B was the best one,followed by group C and group A.As for the overall therapeutic effect,group A was outstanding,followed by group B and group C.Based on the priorities of combat casualty care,the final results of assessment were as follows:group A was the best one,followed by group B and group C.Conclusion The analysis of processes and outcomes of assessment reveals the edge of this model,as evidenced by the continuity of treatment and rescue,integrity of overall effectiveness,and adaptability of this assessment model.

Objective　To perform the pathogenic and genomics analyses on isolates of Streptococcus suis (Ss) from three human infections in Shenzhen, aiming to provide a basis for the prevention and control of Ss outbreaks. Methods　The suspected bacterial strains from three blood plate cultures of three critically ill patients in three hospitals were subjected to biochemical identification, matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS), and real-time fluorescent PCR identification, resulting in the identification of three strains positive for Streptococcus suis serotype 2(SS2). Pure positive cultures were taken for an antimicrobial susceptibility test and extracted nucleic acids for whole-genome sequencing and analysis. The whole-genome sequencing and analysis included species identification, antibiotic resistance genes alignment, multilocus sequence typing (MLST), virulence genes alignment, and coregene-based phylogenetic tree analysis. Results　The blood agar isolates from three patients were all identified as Ss, the VITEK 2 identified them as SS2, and MALDI-TOF-MS identified them as Ss. Real-time PCR results for the universal gene gdh and serotype 2 cps2 gene of Ss were both positive. The antimicrobial susceptibility test results showed that all three strains were resistant to erythromycin and clindamycin, with variable sensitivity to tetracycline. Whole-genome sequencing results showed that all three strains were identified as Ss, including one ST7 strain and two ST1 strains. The virulence gene prediction results based on the VFDB database showed that all three strains were positive for mrp, sly, and cps, indicating high virulence gene characteristics. The analysis of the phylogenetic tree based on coregene showed that the three strains were in different evolutionary branches, with two ST1 strains having a closer evolutionary distance. Conclusions　The pathogens responsible for these three critically ill patients were SS2, and all three strains were resistant to erythromycin and clindamycin. Genetically, they all carried virulence genes that are found in highly virulent strains, while showed differences in MLST typing and phylogenetic tree analysis, indicating the presence of different genotypes of high pathogenicity SS2 in Shenzhen area and had caused sporadic cases, which requires high attention.

Objective To prepare a high performance electrochemical immunosensor for detecting Brucella abortus(B.abortus).Methods Prussian blue(PB),multi walled carbon nanotubes(MWCNTs)and gold nanoparticles(GNPs)(PB-MWCNTs-GNPs)nanocomposites were prepared,and appropriate antibody was used to construct the immunosensor for detecting B.abortus samples.The optimal conditions were clarified by examining the key factors in sensor construction,and then the performance of the sensor was evaluated.Results The optimal construction conditions were determined as follows:the ratio of MWCNTs-PB was 1∶5,the drying temperature was 37 ℃,the pH value of buffer system was 7.5,and the incubation time of antibody and sample was 1 h and 30 min,respectively.B.abortus exhibited a good linear relationship,when ranging from 10 to 1 × 105 CFU/mL.The sensor had good anti-interference ability,repeatability,stability and high accuracy.Conclusion Our prepared PB-MWCNTs GNPs nanomaterials modified electrochemical immunosensor for detecting B.abortus is easy to prepare,has good performance,and can provide reference for the early clinical diagnosis of brucellosis.