Purpose To explore the consistency between T2 mapping and three-dimensional water-selective cartilage(3D-WATSc)sequence measurement of knee cartilage volume.Materials and Methods A total of 30 healthy volunteers were recruited and underwent 3D-WATSc and T2 mapping sequence scans of the left knee joint in the Affiliated Lihuili Hospital of Ningbo University from May to December 2022.A total of 20 subjects'T2 mapping sequences were randomly selected and eight groups of raw images with different TE(13,26,39,52,65,78,91,104 ms)were analyzed.The quality of the raw images was rated by two observers,and the consistency of two observers'scores were subjected by Kappa test.The TE value with the best image quality was determined via Welch analysis of variance and Games-Howell text post hoc test.Based on T2 mapping and 3D-WATSc sequences,semi-automatic segmentation measurements were performed on the cartilage volume of femoral condyle,tibial plateau and patellar posterior margin in 30 subjects.Intra group correlation coefficient(ICC)and Bland-Altman plot were used to test the consistency of cartilage volume between two observers under T2 mapping sequence,as well as between T2 mapping and 3D-WATSc sequences.Results The consistency of the scores of the two observers was moderate except for poor consistency at TE 104 ms(Kappa=0.318)and no statistical difference at TE 78 ms(P=0.052),with Kappa values greater than 0.40 and P<0.05,further analysis showed that the cartilage display quality score was optimal at TE 26 ms(M=2.90).Comparing TE 26 ms with the scores of the other seven groups in Games Howell text,except for TE 26 ms and TE 13 ms(M=2.55),TE 26 ms and TE 39 ms(M=2.62),which had no statistically significant difference in scores(P>0.05),there were significant differences in scores between TE 26 ms and the other TE groups(all P<0.05).On the T2 mapping(TR 2 000 ms,TE 26 ms)sequence,the ICC values of the cartilage volumes of each part segmented by two observers were all greater than 0.6,P<0.05,with the consistency of femoral condyle cartilage volume being the best(ICC=0.877,P<0.01).The consistency of the cartilage volumes of each part measured by 3D-WATSc and T2 mapping sequences was good(ICC>0.75,P<0.01),with the consistency of tibial plateau cartilage volume being the best(ICC=0.857,P<0.01).Conclusion The T2 mapping original grayscale image(TR 2 000 ms,TE 26 ms)can clearly display the morphology of knee joint cartilage,the consistency between T2 mapping and 3D-WATSc sequences in quantifying knee cartilage volume is good,and the T2 mapping single sequence provides a reliable scanning scheme for one-stop quantitative analysis of knee joint cartilage morphology and function.

Objective To understand the changing composition and antibiotic resistance of bacterial species in the clinical isolates from outpatient and emergency department(hereinafter referred to as outpatients)and inpatient children over time in various hospitals,and to provide laboratory evidence for rational antibiotic use.Methods The data on clinically isolated pathogenic bacteria and antimicrobial susceptibility of isolates from outpatients and inpatient children in the CHINET program from 2015 to 2021 were collected and analyzed.Results A total of 278 471 isolates were isolated from pediatric patients in the CHINET program from 2015 to 2021.About 17.1％of the strains were isolated from outpatients,primarily group A β-hemolytic Streptococcus,Escherichia coli,and Staphylococcus aureus.Most of the strains(82.9％)were isolated from inpatients,mainly SS.aureus,E.coli,and H.influenzae.The prevalence of methicillin-resistant S.aureus(MRSA)in outpatients(24.5％)was lower than that in inpatient children(31.5％).The MRSA isolates from outpatients showed lower resistance rates to the antibiotics tested than the strains isolated from inpatient children.The prevalence of vancomycin-resistant Enterococcus faecalis or E.faecium and penicillin-resistant S.pneumoniae was low in either outpatients or inpatient children.S.pneumoniae,β-hemolytic Streptococcus and S.viridans showed high resistance rates to erythromycin.The prevalence of erythromycin-resistant group A β-hemolytic Streptococcus was higher in outpatients than that in inpatient children.The prevalence of β-lactamase-producing H.influenzae showed an overall upward trend in children,but lower in outpatients(45.1％)than in inpatient children(59.4％).The prevalence of carbapenem-resistant Klebsiella pneumoniae(CRKpn),carbapenem-resistant Pseudomonas aeruginosa(CRPae)and carbapenem-resistant Acinetobacter baumannii(CRAba)was 14％,11.7％,47.8％in outpatients,but 24.2％,20.6％,and 52.8％in inpatient children,respectively.The prevalence of multidrug-resistant E.coli,K.pneumoniae,Proteus mirabilis,P.aeruginosa and A.baumannii strains was lower in outpatients than in inpatient children.The prevalence of fluoroquinolone-resistant E.coli,ESBLs-producing K.pneumoniae,ESBLs-producing P.mirabilis,carbapenem-resistant E.coli(CREco),CRKpn,and CRPae was lower in children in outpatients than in inpatient children,but the prevalence of CRAba in 2021 was higher than in inpatient children.Conclusions The distribution of clinical isolates from children is different between outpatients and inpatients.The prevalence of MRSA,ESBL,and CRO was higher in inpatient children than in outpatients.Antibiotics should be used rationally in clinical practice based on etiological diagnosis and antimicrobial susceptibility test results.Ongoing antimicrobial resistance surveillance and prevention and control of hospital infections are crucial to curbing bacterial resistance.

Objective To examine the changing prevalence and antimicrobial resistance profiles of Burkholderia cepacia in 52 hospitals across China from 2015 to 2021.Methods A total of 9 261 strains of B.cepacia were collected from 52 hospitals between January 1,2015 and December 31,2021.Antimicrobial susceptibility of the strains was tested using Kirby-Bauer method or automated antimicrobial susceptibility testing systems according to a unified protocol.The results were interpreted according to the breakpoints released in the Clinical & Laboratory Standards Institute(CLSI)guidelines(2023 edition).Results A total of 9 261 strains of B.cepacia were isolated from all age groups,especially elderly patients.The proportion was 11.1％(1 032 strains)in children,significantly lower than the proportion in adults.About half(46.5％,4 310/9 261)of the strains were isolated from patients at least 60 years old and 42.3％(3 919/9 261)of the strains were isolated from young adults.Most isolates(71.1％)were isolated from sputum and respiratory secretions,followed by urine(10.7％)and blood samples(8.1％).B.cepacia isolates were highly susceptible to the five antimicrobial agents recommended in the CLSI M100 document(33rd edition,2023).B.cepacia isolates showed relatively higher resistance rates to meropenem and levofloxacin.However,the resistance rates to ceftazidime,trimethoprim-sulfamethoxazole,and minocycline remained below 8.1％.The percentage of B.cepacia strains resistant to levofloxacin was the highest compared to other antibiotics in any of the three age groups(from 12.4％in the patients＜18 years old to 20.6％in the patients aged 60 years or older).Conclusions B.cepacia is one of the clinically important non-fermenting gram-negative bacteria.Accurate and timely reporting of antimicrobial susceptibility test results and ongoing antimicrobial resistance surveillance are helpful for rational prescription of antimicrobial agents and proper prevention and control of nosocomial infections.

Objective To investigate the application value of ultrasonic artificial intelligence(AI)combined with serine/threonine-protein kinase(BRAF)V600E gene testing in differentiating benign-malignant and invasive thyroid nodules.Methods A total of 150 patients with malignant thyroid nodules(the malignant group)and 150 patients with benign thyroid nodules(the benign group)were selected.According to whether the pathological diagnosis of the malignant group involved capsule,vascular,nerve invasion or lymph node metastasis,patients were divided into the invasive group(66 cases)and the non-invasive group(84 cases).General clinical characteristics,ultrasonic AI parameters and BRAF V600E gene testing results were compared between groups.Discrepancies between ultrasonic AI,BRAF V600E gene testing and postoperative pathological diagnoses were analyzed.ROC curves and Delong tests were usd to evaluate the diagnostic efficacy of ultrasonic AI,BRAF V600E gene and their joint inspection.Results The malignant group exhibited higher probabilities of nodule maximum diameter(＞1 cm),solid structure,hypoechoic/very hypoechoic echogenicity,microcalcification,blurred margin,irregular shape,aspect ratio(＞1),internal and mixed blood flow distribution and high blood flow richness(gradesⅢ—Ⅴ)compared to those of the benign group(P＜0.05).The invasive subgroup showed higher probabilities of nodule maximum diameter(＞1 cm),solid structure,hypoechoic/very hypoechoic echogenicity,microcalcification,blurred margin,irregular shape,internal and mixed blood flow distribution,and high blood flow richness(grades Ⅲ—Ⅴ)than those of the non-invasive subgroup(P＜0.05).For diagnosing malignant thyroid nodules,ultrasonic AI demonstrated a sensitivity of 90.00%and specificity of 80.67%.For invasive malignant nodules,sensitivity was 84.85%and specificity was 83.33%.BRAF V600E gene testing showed a sensitivity of 72.67%,specificity of 90.00%for malignant nodules.For invasive nodules,sensitivity was 74.24%and specificity was 88.10%.Receiver operating characteristic curve(ROC)analysis revealed that the AUCs(95%CI)for ultrasonic AI,BRAF V600E gene and their joint inspection in diagnosing malignant thyroid nodules were 0.853(0.807-0.900),0.813(0.762-0.864)and 0.941(0.917-0.966),with the joint inspection outperforming individual tests(P＜0.05).For invasive malignant nodules,the AUCs were 0.841(0.773-0.909),0.812(0.737-0.886)and 0.924(0.880-0.967),respectively,with the joint inspection showing superior performance(P＜0.05).Conclusion The joint inspection ultrasound AI with BRAF V600E gene significantly improve the diagnostic efficacy for differentiating benign and malignant thyroid nodules,and assessing their invasive potential.

Objective To summarize the changing prevalence of carbapenem resistance in Enterobacterales based on the data of CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021 for improving antimicrobial treatment in clinical practice.Methods Antimicrobial susceptibility testing was performed using a commercial automated susceptibility testing system according to the unified CHINET protocol.The results were interpreted according to the breakpoints of the Clinical & Laboratory Standards Institute(CLSI)M100 31st ed in 2021.Results Over the seven-year period(2015-2021),the overall prevalence of carbapenem-resistant Enterobacterales(CRE)was 9.43％(62 342/661 235).The prevalence of CRE strains in Klebsiella pneumoniae,Citrobacter freundii,and Enterobacter cloacae was 22.38％,9.73％,and 8.47％,respectively.The prevalence of CRE strains in Escherichia coli was 1.99％.A few CRE strains were also identified in Salmonella and Shigella.The CRE strains were mainly isolated from respiratory specimens(44.23±2.80)％,followed by blood(20.88±3.40)％and urine(18.40±3.45)％.Intensive care units(ICUs)were the major source of the CRE strains(27.43±5.20)％.CRE strains were resistant to all the β-lactam antibiotics tested and most non-β-lactam antimicrobial agents.The CRE strains were relatively susceptible to tigecycline and polymyxins with low resistance rates.Conclusions The prevalence of CRE strains was increasing from 2015 to 2021.CRE strains were highly resistant to most of the antibacterial drugs used in clinical practice.Clinicians should prescribe antimicrobial agents rationally.Hospitals should strengthen antibiotic stewardship in key clinical settings such as ICUs,and take effective infection control measures to curb CRE outbreak and epidemic in hospitals.

Objective To characterize the changing species distribution and antibiotic resistance profiles of respiratory isolates in hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Methods Commercial automated antimicrobial susceptibility testing systems and disk diffusion method were used to test the susceptibility of respiratory bacterial isolates to antimicrobial agents following the standardized technical protocol established by the CHINET program.Results A total of 589 746 respiratory isolates were collected from 2015 to 2021.Overall,82.6％of the isolates were Gram-negative bacteria and 17.4％were Gram-positive bacteria.The bacterial isolates from outpatients and inpatients accounted for(6.0±0.9)％and(94.0±0.1)％,respectively.The top microorganisms were Klebsiella spp.,Acinetobacter spp.,Pseudomonas aeruginosa,Staphylococcus aureus,Haemophilus spp.,Stenotrophomonas maltophilia,Escherichia coli,and Streptococcus pneumoniae.Each microorganism was isolated from significantly more males than from females(P＜0.05).The overall prevalence of methicillin-resistant S.aureus(MRSA)was 39.9％.The prevalence of penicillin-resistant S.pneumoniae was 1.4％.The prevalence of extended-spectrum β-lactamase(ESBL)-producing E.coli and K.pneumoniae was 67.8％and 41.3％,respectively.The overall prevalence of carbapenem-resistant E.coli,K.pneumoniae,Enterobacter cloacae,Pseudomonas aeruginosa,and Acinetobacter baumannii was 3.7％,20.8％,9.4％,29.8％,and 73.3％,respectively.The prevalence of β-lactamase was 96.1％in Moraxella catarrhalis and 60.0％in Haemophilus influenzae.The H.influenzae isolates from children(＜18 years)showed significantly higher resistance rates to β-lactam antibiotics than the isolates from adults(P＜0.05).Conclusions Gram-negative bacteria are still predominant in respiratory isolates associated with serious antibiotic resistance.Antimicrobial resistance surveillance should be strengthened in clinical practice to support accurate etiological diagnosis and appropriate antimicrobial therapy based on antimicrobial susceptibility testing results.

Objective To summarize the changing prevalence of carbapenem resistance in Enterobacterales based on the data of CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021 for improving antimicrobial treatment in clinical practice.Methods Antimicrobial susceptibility testing was performed using a commercial automated susceptibility testing system according to the unified CHINET protocol.The results were interpreted according to the breakpoints of the Clinical & Laboratory Standards Institute(CLSI)M100 31st ed in 2021.Results Over the seven-year period(2015-2021),the overall prevalence of carbapenem-resistant Enterobacterales(CRE)was 9.43％(62 342/661 235).The prevalence of CRE strains in Klebsiella pneumoniae,Citrobacter freundii,and Enterobacter cloacae was 22.38％,9.73％,and 8.47％,respectively.The prevalence of CRE strains in Escherichia coli was 1.99％.A few CRE strains were also identified in Salmonella and Shigella.The CRE strains were mainly isolated from respiratory specimens(44.23±2.80)％,followed by blood(20.88±3.40)％and urine(18.40±3.45)％.Intensive care units(ICUs)were the major source of the CRE strains(27.43±5.20)％.CRE strains were resistant to all the β-lactam antibiotics tested and most non-β-lactam antimicrobial agents.The CRE strains were relatively susceptible to tigecycline and polymyxins with low resistance rates.Conclusions The prevalence of CRE strains was increasing from 2015 to 2021.CRE strains were highly resistant to most of the antibacterial drugs used in clinical practice.Clinicians should prescribe antimicrobial agents rationally.Hospitals should strengthen antibiotic stewardship in key clinical settings such as ICUs,and take effective infection control measures to curb CRE outbreak and epidemic in hospitals.

Objective To characterize the changing species distribution and antibiotic resistance profiles of respiratory isolates in hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Methods Commercial automated antimicrobial susceptibility testing systems and disk diffusion method were used to test the susceptibility of respiratory bacterial isolates to antimicrobial agents following the standardized technical protocol established by the CHINET program.Results A total of 589 746 respiratory isolates were collected from 2015 to 2021.Overall,82.6％of the isolates were Gram-negative bacteria and 17.4％were Gram-positive bacteria.The bacterial isolates from outpatients and inpatients accounted for(6.0±0.9)％and(94.0±0.1)％,respectively.The top microorganisms were Klebsiella spp.,Acinetobacter spp.,Pseudomonas aeruginosa,Staphylococcus aureus,Haemophilus spp.,Stenotrophomonas maltophilia,Escherichia coli,and Streptococcus pneumoniae.Each microorganism was isolated from significantly more males than from females(P＜0.05).The overall prevalence of methicillin-resistant S.aureus(MRSA)was 39.9％.The prevalence of penicillin-resistant S.pneumoniae was 1.4％.The prevalence of extended-spectrum β-lactamase(ESBL)-producing E.coli and K.pneumoniae was 67.8％and 41.3％,respectively.The overall prevalence of carbapenem-resistant E.coli,K.pneumoniae,Enterobacter cloacae,Pseudomonas aeruginosa,and Acinetobacter baumannii was 3.7％,20.8％,9.4％,29.8％,and 73.3％,respectively.The prevalence of β-lactamase was 96.1％in Moraxella catarrhalis and 60.0％in Haemophilus influenzae.The H.influenzae isolates from children(＜18 years)showed significantly higher resistance rates to β-lactam antibiotics than the isolates from adults(P＜0.05).Conclusions Gram-negative bacteria are still predominant in respiratory isolates associated with serious antibiotic resistance.Antimicrobial resistance surveillance should be strengthened in clinical practice to support accurate etiological diagnosis and appropriate antimicrobial therapy based on antimicrobial susceptibility testing results.

Objective:To explore highly efficient ventilation protection technology for large-space workplaces adapted to the production process in composite material impregnation.Methods:A composite material impregnation room was selected as the research subject from August to December 2023. Occupational health investigation, on-site detection, and physical simulation of air distribution were used to analyze the distribution of the xylene concentrations in the impregnation room. In addition, the causes for excessive concentrations were analyzed, and the combination ventilation design of enclosed negative pressure cabinets and jet directional supply of fresh air was proposed. The concentration of xylene, the capture velocity and the differential pressure of ventilation facilities before and after the transformation were tested on the spot. The rationality of the airflow organization was determined through smoke testing, and the ventilation protection effects before and after the transformation were analyzed.Results:The time-weighted average allowable concentration ( CTWA) of xylene was reduced from 41.73 mg/m 3 to 7.78 mg/m 3, and the CTWA of xylene were reduced by 81.4%. The values of capture velocity at all areas were higer than 0.5 m/s, and the values of velocity unevenness in all regions were lower than or equal to 0.25. The differential pressure between the enclosed cabinet and the impregnation room corridor was -2 to -1 Pa. The overall velocity distribution at all areas was relatively uniform, the airflow organization was reasonable, and negative pressure was formed inside the enclosed cabinet. Conclusion:The combination ventilation design of xylene, the capture velocity and the differential pressure of ventilation facilities effectively reducing the xylene concentration in the workplace, and provide a reference for ventilation protection of xylene workplace.

Objective To investigate the distribution and antimicrobial resistance profiles of common pathogens isolated from cerebrospinal fluid(CSF)in CHINET program from 2015 to 2021.Methods The bacterial strains isolated from CSF were identified in accordance with clinical microbiology practice standards.Antimicrobial susceptibility test was conducted using Kirby-Bauer method and automated systems per the unified CHINET protocol.Results A total of 14 014 bacterial strains were isolated from CSF samples from 2015 to 2021,including the strains isolated from inpatients(95.3％)and from outpatient and emergency care patients(4.7％).Overall,19.6％of the isolates were from children and 80.4％were from adults.Gram-positive and Gram-negative bacteria accounted for 68.0％and 32.0％,respectively.Coagulase negative Staphylococcus accounted for 73.0％of the total Gram-positive bacterial isolates.The prevalence of MRSA was 38.2％in children and 45.6％in adults.The prevalence of MRCNS was 67.6％in adults and 69.5％in children.A small number of vancomycin-resistant Enterococcus faecium(2.2％)and linezolid-resistant Enterococcus faecalis(3.1％)were isolated from adult patients.The resistance rates of Escherichia coli and Klebsiella pneumoniae to ceftriaxone were 52.2％and 76.4％in children,70.5％and 63.5％in adults.The prevalence of carbapenem-resistant E.coli and K.pneumoniae(CRKP)was 1.3％and 47.7％in children,6.4％and 47.9％in adults.The prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)and Pseudomonas aeruginosa(CRPA)was 74.0％and 37.1％in children,81.7％and 39.9％in adults.Conclusions The data derived from antimicrobial resistance surveillance are crucial for clinicians to make evidence-based decisions regarding antibiotic therapy.Attention should be paid to the Gram-negative bacteria,especially CRKP and CRAB in central nervous system(CNS)infections.Ongoing antimicrobial resistance surveillance is helpful for optimizing antibiotic use in CNS infections.