Objective: To understand the association between weight-adjusted-waist index (WWI) and cardiopulmonary endurance among middle school students, so as to provide references for the improvement of cardiopulmonary endurance levels in adolescents. Methods: From June 2015 to December 2018 by using the method of purposive sampling, height, weight, waist circumference, and 20 m shuttle-run tests were measured among 44 870 adolescents aged 13-18 from Northeast, North, East, South, Southwest and Northwest of China. The WWI of the adolescents and the maximum oxygen uptake (VO 2max ) were calculated indirectly. The t-test and one way analysis of variance were used for comparison, and the curve regression analysis method was adopted to analyze the relationship between WWI and VO 2max . Results: For Chinese middle school students aged 13-18, the WWI was (9.35±1.02), the number of 20 m shuttle-run was (38.89±18.14) times, and VO 2max was (39.96±5.88) mL/(kg ·min -1 ). The differences of VO 2max between WWI quartile arrays of boys aged 13-18 were statistically significant ( F=15.19, 9.00, 14.97, 20.48, 28.13, 10.13 , P <0.01), girls had the same trend ( F=23.36, 16.61, 33.45, 32.96, 18.23, 19.36, P <0.01). There was an inverted U shaped curve relationship between WWI and cardiopulmonary endurance. When WWI was 8.5, the VO 2max level reached the highest, which was 40.07 mL/(kg ·min -1 ). Compared with girls, WWI in boys had a more significant impact on cardiopulmonary endurance. Conclusion Maintaining optimal WWI levels may enhance adolescents cardiopulmonary endurance.

In recent years, the deep integration of artificial intelligence (AI) into medical education has created new opportunities for teaching Biochemistry and Molecular Biology, while also offering innovative solutions to the pedagogical challenges associated with protein structure and function. Focusing on the case of anaplastic lymphoma kinase (ALK) gene mutations in non-small-cell lung cancer (NSCLC), this study integrates AI into case-based learning (CBL) to develop an AI-CBL hybrid teaching model. This model features an intelligent case-generation system that dynamically constructs ALK mutation scenarios using real-world clinical data, closely linking molecular biology concepts with clinical applications. It incorporates AI-powered protein structure prediction tools to accurately visualize the three-dimensional structures of both wild-type and mutant ALK proteins, dynamically simulating functional abnormalities resulting from conformational changes. Additionally, a virtual simulation platform replicates the ALK gene detection workflow, bridging theoretical knowledge with practical skills. As a result, a multidimensional teaching system is established—driven by clinical cases and integrating molecular structural analysis with experimental validation. Teaching outcomes indicate that the three-dimensional visualization, dynamic interactivity, and intelligent analytical capabilities provided by AI significantly enhance students’ understanding of molecular mechanisms, classroom engagement, and capacity for innovative research. This model establishes a coherent training pathway linking “fundamental theory-scientific research thinking-clinical practice”, offering an effective approach to addressing teaching challenges and advancing the intelligent transformation of medical education.

Intravenous thrombolysis and revascularisation are subject to strict time windows,and most patients still need to reperfuse ischaemic tissue through their own compensatory mechanisms due to subsequent re-occlusion or"no-reflow".A good collateral circulation can prolong the therapeutic window,increase the tolerance of brain tissue to ischaemia and hypoxia,and improve the prognosis,so promoting the establishment of collateral circulation to improve ischaemic tissue perfusion is a new idea in the treatment of ischaemic stroke.In this paper,we provides a review of relevant studies on methods of assessment of collateral circulation,therapeutic approaches,and clinical significance to provide guidance for the treatment of ischaemic stroke.

The prevalence of dilated cardiomyopathy （DCM） has been increasing year by year，which seriously endangers the physical and mental health of patients. Establishing an animal model that conforms to the clinical characteristics of the disease is a prerequisite for conducting experimental research on DCM. This study sorted out and summarized the commonly used DCM animal models and evaluated the degree of consistency between the models and clinical practice based on the etiology and pathogenesis of traditional Chinese and western medicine and clinical diagnostic criteria. The models with high consistency with western medicine include immune models，drug toxicity models，and tachycardia models，while the models with high consistency with traditional Chinese medicine include drug toxicity models，gene correlation models，and tachycardia models. With consideration of the characteristics of the symptoms，consistency，and their respective advantages and disadvantages，the more ideal models are drug toxicity models，tachycardia models，and gene correlation models. In addition to evaluating the clinical consistency of traditional Chinese and western medicine in DCM animal models，this study also analyzed the advantages and disadvantages of existing DCM animal models，existing problems，and observation indicators of the models and pointed out the lack of standardized and unified syndrome model differentiation standards. Due to the complexity of the disease and the unclear pathogenesis，there are few studies on DCM models，and there is room for improvement. On this basis，four improvement directions are proposed to make the animal models as close to the clinical pathological and physiological processes as possible，so that the combination of disease and syndrome in animal models is more practical. These animal models can provide an experimental basis for the pathogenesis，drug intervention，efficacy evaluation，and scientific research of DCM and better serve scientific research and clinical practice.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of national bloodstream infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:During the study period，9 035 strains of Gram-negative bacteria were collected from 51 hospitals，of which 7 895（87.4%）were Enterobacteriaceae and 1 140（12.6%）were non-fermenting bacteria. The top 5 bacterial species were Escherichia coli（ n=4 510，49.9%）， Klebsiella pneumoniae（ n=2 340，25.9%）， Pseudomonas aeruginosa（ n=534，5.9%）， Acinetobacter baumannii complex（ n=405，4.5%）and Enterobacter cloacae（ n=327，3.6%）. The ESBLs-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus spp. were 47.1%（2 095/4 452），21.0%（427/2 033）and 41.1%（58/141），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（58/4 510）and 13.1%（307/2 340）；62.1%（36/58）and 9.8%（30/307）of CREC and CRKP were resistant to ceftazidime/avibactam combination，respectively. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 59.5%（241/405），while less than 5% of Acinetobacter baumannii complex was resistant to tigecycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 18.4%（98/534）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of main Gram-negative bacteria resistance among different regions，with statistically significant differences in the prevalence of CRKP and CRPA（ χ2=20.489 and 20.252， P<0.001）. The prevalence of CREC，CRKP，CRPA，CRAB，ESBLs-producing Escherichia coli and Klebsiella pneumoniae were higher in provinicial hospitals than those in municipal hospitals（ χ2=11.953，81.183，10.404，5.915，12.415 and 6.459， P<0.01 or <0.05），while the prevalence of CRPA was higher in economically developed regions（per capita GDP ≥ 92 059 Yuan）than that in economically less-developed regions（per capita GDP <92 059 Yuan）（ χ2=6.240， P=0.012）. Conclusions:The proportion of Gram-negative bacteria in bloodstream infections shows an increasing trend，and Escherichia coli is ranked in the top，while the trend of CRKP decreases continuously with time. Decreasing trends are noted in ESBLs-producing Escherichia coli and Klebsiella pneumoniae. Low prevalence of carbapenem resistance in Escherichia coli and high prevalence in CRAB complex have been observed. The composition ratio and antibacterial spectrum of bloodstream infections in different regions of China are slightly different，and the proportion of main drug resistant bacteria in provincial hospitals is higher than those in municipal hospitals.

β-lactams,including penicillin,have been used for over 80 years in the treatment of group A Streptococcus(GAS)infections.Although β-lactam-resistant GAS strains have not been identified in vitro tests,clinical treatment failures have been reported since the 1950s.The mechanism underlying the clinical failure of β-lactam treatment in GAS infections remains unclear.Previous research has suggested that β-lactam resistance in GAS in vivo is associated with reduced drug susceptibility of strains,bacterial inoculation effects,biofilm formation,the effect of coexisting bacteria,bacterial persistence,and bacterial internalization into host cells.This article reviews the main reports on β-lactam treatment failure in GAS infections and analyzes the possible mechanisms of β-lactam resistance in vivo.The findings aim to contribute to future research and clinical approaches in the field.

Objective:To establish a method for the determination of eight N-nitrosamines (N-nitrosodimethylamine, N-nitrosodimethylamine, N-nitrosomethylmethylamine, N-nitrosodibutylamine, N-nitrosopropylamine, N-nitrosomorpholine, N-nitrosodianiline and N-nitrosopiperidine) in the air of workplace by gas chromatography-tandem mass spectrometry (GC-MS/MS) .Methods:From January to August 2023, eight N-nitrosamines in the air of workplace were collected by ThermoSorb/N column, eluted with 4 ml methanol-dichloromethane (1∶1 volume ratio), separated by VF-624 ms capillary column, detected by multiple reaction monitoring mode and quantified by external standard method. The detection limit and precision of the method were also analyzed.Results:The linear range of the method for the determination of eight N-nitrosamines was 1.0-20.0 μg/L, the correlation coefficient was 0.9993-0.9999, the detection limit was 0.051-0.132 μg/L, and the minimum quantitative concentration was 0.030-0.078 μg/m 3 (calculated by collecting 22.5 L of air sample and eluting with 4.0 ml stripping liquid). The within-run precisions were 2.05%-6.89% and the between-run precisions were 2.41%-8.26%. The desorption rates were 67.20%-102.60%. The sample can be kept at least 7 days at 4 ℃. Conclusion:GC-MS/MS method for the determination of eight N-nitrosamines in workplace air has high sensitivity and good precision, and can accurately determine the content of eight N-nitrosamines in workplace air.

Objective:To establish a method for the determination of eight N-nitrosamines (N-nitrosodimethylamine, N-nitrosodimethylamine, N-nitrosomethylmethylamine, N-nitrosodibutylamine, N-nitrosopropylamine, N-nitrosomorpholine, N-nitrosodianiline and N-nitrosopiperidine) in the air of workplace by gas chromatography-tandem mass spectrometry (GC-MS/MS) .Methods:From January to August 2023, eight N-nitrosamines in the air of workplace were collected by ThermoSorb/N column, eluted with 4 ml methanol-dichloromethane (1∶1 volume ratio), separated by VF-624 ms capillary column, detected by multiple reaction monitoring mode and quantified by external standard method. The detection limit and precision of the method were also analyzed.Results:The linear range of the method for the determination of eight N-nitrosamines was 1.0-20.0 μg/L, the correlation coefficient was 0.9993-0.9999, the detection limit was 0.051-0.132 μg/L, and the minimum quantitative concentration was 0.030-0.078 μg/m 3 (calculated by collecting 22.5 L of air sample and eluting with 4.0 ml stripping liquid). The within-run precisions were 2.05%-6.89% and the between-run precisions were 2.41%-8.26%. The desorption rates were 67.20%-102.60%. The sample can be kept at least 7 days at 4 ℃. Conclusion:GC-MS/MS method for the determination of eight N-nitrosamines in workplace air has high sensitivity and good precision, and can accurately determine the content of eight N-nitrosamines in workplace air.

Objective:Melanoma is highly malignant and heterogeneous.It is essential to develop a specific prognostic model for improving the patients'survival and treatment strategies.Recent studies have shown that ferroptosis results from the overproduction of lipid peroxidation and is an iron-dependent form of programmed cell death.Despite this,ferroptosis-related genes(FRGs)and their clinical significances remain unknown in malignant melanoma.This study aims to assess the role of FRGs in melanoma,with the goal of developing a novel prognostic model that provides new insights into personalized treatment and improvement of therapeutic outcomes for melanoma. Methods:We systematically characterized the genetic alterations and mRNA expression of 73 FRGs in The Cancer Genome Atlas(TCGA)-skin cutaneous melanoma(SKCM)dataset in this study.The results were validated with real-time RT-PCR and Western blotting.Subsequently,a multi-gene feature model was constructed using the TCGA-SKCM cohort.Melanoma patients were classified into a high-risk group and a low-risk group based on the feature model.As a final step,correlations between ferroptosis-related signatures and immune features,immunotherapy efficacy,or drug response were analyzed. Results:By analyzing melanoma samples from TCGA-SKCM dataset,FRGs exhibited a high frequency of genetic mutations and copy number variations(CNVs),significantly impacting gene expression.Additionally,compared with normal skin tissue,30 genes with significantly differential expression were identified in melanoma tissues.A prognostic model related to FRGs,constructed using the LASSO Cox regression method,identified 13 FRGs associated with overall survival prognosis in patients and was validated with external datasets.Finally,functional enrichment and immune response analysis further indicated significant differences in immune cell infiltration,mutation burden,and hypoxia status between the high-risk group and the low-risk group,and the model was effective in predicting responses to immunotherapy and drug sensitivity. Conclusion:This study develops a strong ferroptosis-related prognostic signature model which could put forward new insights into target therapy and immunotherapy for patients with melanoma.

Objective To measure the distance between the lateral compression Ⅱ(LC-Ⅱ)screw guide needle and the surrounding important structures around the anterior inferior iliac spine in pelvic fractures and to locate the needle point,so as to provide anatomical reference for clinical nail placement.Methods Totally 40 adult gross specimens of embalming were implanted with LC-Ⅱ screw guide needle under the surveillance of C-arm machine,and the specimens were dissected.The shortest distance between the insertion point and the lateral femoral cutaneous nerve,femoral nerve,femoral artery,femoral vein,anterior superior iliac spine and inguinal ligament was measured.The triangle was constructed between the insertion point,anterior superior iliac spine and inguinal ligament,and the exact location of the entry point was calculated.Results The average distance between the insertion point of the male needle and the femoral vein was(50.67±7.29)mm＞the anterior superior iliac spine(43.83±7.58)mm＞the femoral artery(38.35±6.63)mm＞the femoral nerve(31.17±1.67)mm=the inguinal ligament(28.69±6.59)mm＞the lateral femoral cutaneous nerve(7.98±3.81)mm.The mean distance between the insertion point of the female needle and the anterior superior iliac spine was(45.28±7.07)mm=femoral vein(43.72±6.89)mm＞femoral artery(33.76±6.33)mm＞femoral nerve(25.66±6.46)mm=inguinal ligament(23.22±5.00)mm＞lateral femoral cutaneous nerve(8.97±4.76)mm.The projection distance of the entry point was 31.77 mm for men and 38.41 mm for women.The Angle b was 42.81°for men and 31.71° for women.Conclusion The lateral femoral cutaneous nerve is most vulnerable to injury when LC-Ⅱ screw is inserted,and the risk of injury has nothing to do with sex.The insertion point positioning method a and b made LC-Ⅱ screw placement quickly,safely and accurately,and reduced fluoroscopy time and frequency.