Objective:To report the nationwide surveillance results of pathogenic profiles and antimicrobial resistance patterns of Gram-positive bloodstream infections in China in 2023.Methods:The clinical isolates of Gram-posttive bacteria from blood cultures were collected in member hospitals of National Bloodstream Infection Bacterial Resistant Investigation Collaborative System（BRICS）during January to December 2023. Antimicrobial susceptibility testing was performed using the dilution method recommended by the Clinical and Laboratory Standards Institute（CLSI）. Statistical analyses were conducted using WHONET 5.6 and SPSS 25.0 software.Results:A total of 4 385 Gram-positive bacterial isolates were obtained from 60 participating center. The top five pathogens were Staphylococcus aureus（ n=1 544，35.2%），coagulase-negative Staphylococci（ n=1 441，32.9%）， Enterococcus faecium（ n=574，13.1%）， Enterococcus faecalis（ n=385，8.8%），and α-hemolytic Streptococci（ n=187，4.3%）. The prevalence of methicillin-resistant Staphylococcus aureus（MRSA）and methicillin-resistant coagulase-negative Staphylococci（MRCNS）was 26.2%（405/1 544）and 69.8%（1 006/1 441），respectively. Notably，all Staphylococci remained susceptible to glycopeptide or daptomycin. Staphylococcus aureus demonstrated excellent susceptibility（>97.0%）to cephalobiol，rifampicin，trimethoprim-sulfamethoxazole，linezolid，minocycline，tigecycline，and eravacycline. No Enterococcus exhibiting resistance to linezolid were detected. Glycopeptide resistance was uncommon but more frequent in Enterococcus faecium（resistance to vancomycin and teicoplanin：both 1.7%）compared to Enterococcus faecalis（both 0.3%）. The detection rates of MRSA and MRCNS exhibited significant regional variations across the country（ χ2=17.674 and 148.650，respectively，both P<0.001）. No vancomycin-resistant Enterococci were detected in central China. Institutional comparison demonstrated higher prevalence of MRSA（ χ2=14.111， P<0.001）and MRCNS（ χ2=4.828， P=0.028）in provincial hospitals than that in municipal hospitals. Socioeconomic analysis identified elevated detection rates of both MRSA（ χ2=18.986， P<0.001）and MRCNS（ χ2=4.477， P=0.034）in less developed regions（per capita GDP

Objective:To report the results of bacterial resistant investigation collaborative system（BRICS）on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2023，and provide reference for clinical tretment of bloodstream infections and prevention and control of bacterial resistance.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of BRICS were collected during January 2023 to December 2023. 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 were used to analyze the data.Results:During the study period，11 492 strains of Gram-negative bacteria were collected from 60 hospitals，of which 10 098（87.9%）were Enterobacterales and 1 394（12.1%）were non-fermentative bacteria. The top 5 bacterial species were Escherichia coli（50.0%）， Klebsiella pneumoniae（26.1%）， Pseudomonas aeruginosa（5.1%）， Acinetobacter baumannii complex（5.0%）and Enterobacter cloacae complex（4.1%）. The ESBL-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus mirablilis were 46.8%（2 685/5 741），18.3%（549/2 999）and 44.0%（77/175），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（76/5 741）and 15.0%（450/2 999）；32.9%（25/76）and 78.0%（351/450）of CREC and CRKP were sensitive to ceftazidime/avibactam combination，respectively. 94.7%（72/76）and 90.2%（406/450）of CREC and CRKP were sensitive to aztreonam/avibactam combination. Furthermore，57.9%（44/76）and 79.1%（356/450）were sensitive to imipenem/relebactam combination. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 64.6%（370/573），while more than 80.0% of CRAB complex was sensitive to tigecycline，eravacycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 17.0%（99/581）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of important Gram-negative bacteria resistance among different regions in China，with statistically significant differences in the prevalence of CREC，CRKP，CRPA and CRAB complex（ χ2=10.6，28.6，10.8 and 19.3， P<0.05）. The prevalence of ESBL-producing Escherichia coli， CREC，CRAB complex and CRKP were higher in provincial hospitals than those in municipal hospitals（ χ2=12.5，9.8，12.7 and 57.8，all P<0.01）. Conclusions:Gram-negative bacteria are the main pathogens causing bloodstream infections in China，and Escherichia coli is ranked in the top，while the trend of Klebsiella pneumoniae increases continuously with time. CRKP infection shows a slow upward trend，CREC infecton maintains a low prevalence level，and CRAB complex infection continues to exhibit a high prevalence rate. The composition and resistance patterns of pathogens causing bloodstream infections vary to some extent across different regions and levels of hospitals in China.

Objective:To investigate the factors influencing the delayed onset of intrapartum fever following epidural labor analgesia and their impact on maternal and neonatal outcomes.Methods:Select parturients who experienced intrapartum fever following labor analgesia(T≥38.0℃,age≥18 years,singleton pregnancy,ASA classification Ⅱ)between January 1,2021,and December 31,2023.Group them based on the median time of intra-partum fever onset after labor analgesia:those with onset times less than the median were classified as the ear-ly-onset fever group,and those with onset times greater than the median were classified as the late-onset fever group.Using univariate and multivariate Logistic regression analysis to explore factors influencing the delay in in-trapartum fever onset and the pregnancy outcomes of the mothers and newborns in both groups.Results:A total of 253 parturients were included,and the time range of onset of intrapartum fever following epidural labor analgesi-a was 1.83-28.42 hours,with a median fever onset time of 8.00 hours.There were 126 cases in the early-onset group and 127 in the late-onset group.Multivariate Logistic regression analysis indicated that primiparous women,artificial membrane rupture,and neonatal birth weight were independent risk factors for delayed fever onset(OR＞1,P＜0.05),whereas the administration of oxytocin prior to labor analgesia was found to be a protective factor(OR＜1,P＜0.05).The late-onset group exhibited higher levels of white blood cells(WBC),C-reactive pro-tein,longer hospital stays,higher hospitalization costs,greater diagnosis rates of chorioamnionitis,higher NICU ad-mission rates,as well as a higher incidence of neonatal pneumonia,for newborns compared to the early-onset group(P＜0.05).Conclusions:Primiparous women,artificial membrane rupture,and higher neonatal birth weight may be associated with delayed onset of intrapartum fever,while oxytocin administration prior to labor analgesia may offer some protective benefit.The later the onset of intrapartum fever,the worse the clinical outcomes for both mother and infants.

Sarin(GB)is a typical representative of nerve agents with high toxicity,and very low amount can cause death.GB can cause water and atmospheric environment poisoning,so the detection of GB in water and air is of great significance.In this work,a colorimetric sensor array(CSA)based on GB inhibition of cholinesterase activity was constructed to detect GB with high selectivity.A 4×4 colorimetric array was constructed using acetylcholinesterase(AChE),butyryl cholinesterase(BuChE)and the corresponding substrate acetylthiocholine iodide(S-ACh),butyryl thiocholine iodide(S-BCh),acetylcholine chloride(ACh),butyryl choline chloride(BCh)and 2,6-dichloroindophenol ethyl ester(DCIE).The linear curve of the sensor was Y=131.3×lgC+271.6(R2=0.997),where Y was the array response Euclidean distance,C was the concentration of GB(mg/L),the linear range was 0.03?0.32 mg/L,and the detection limit was 27.6 μg/L.The method could effectively distinguish chemical warfare agents(CWA)such as VX,Soman(GD),mustard gas(HD),Louie reagent(L),and had high anti-interference ability,sensitivity and good repeatability.It was successfully applied to the detection of GB in simulated water and simulated air samples,and the sample recovery rate was 97.2% ?100.9%.This method would be potentially applied to the field rapid detection of nerve agents.

ObjectiveThis study explores the methods of lung tissue extraction and fixation required for pathological studies of fetal rats, based on the unique physiological structure of fetal rat lung tissue and existing lung tissue fixation techniques for adult rats. MethodsSix pregnant adult SD rats at 20.5 days of gestation were subjected to cesarean section to obtain fetal rats. Four healthy fetal rats with similar body weight, vital signs, and respiratory status were selected from each pregnant rat, and they were randomly divided into the following groups using a random number table: direct lung infiltration group, lung infiltration group after intratracheal infusion, whole-body infiltration group of fetal rats, and whole-body infiltration group after intratracheal infusion of fetal rats. To systematically compare and analyze the anatomical morphology under different fixation methods, lung tissues from four groups of fetal rats were harvested, perfused, and fixed, and the gross morphology of lung tissues in each group was observed. Paraffin sections were prepared and stained with Hematoxylin-Eosin (H&E). The histological morphology of the whole lung, alveoli, and bronchi was further examined under optical microscopy. ResultsIn the direct lung infiltration group, the hilar structures were unclear, lung lobation was indistinct, the shape was irregular, lung cavities were small, and alveoli and bronchi were shrunken. In the lung infiltration group after intratracheal infusion, the hilar structures were clear, lobation was pronounced, the shape was regular, lung cavities were large, and alveoli and bronchi were full. Both the whole-body infiltration group and whole-body infiltration group after intratracheal infusion of fetal rats exhibited visible lungs, hearts, skins, and other organs. The lung tissues of both groups showed obvious lobulation, irregular shape, and damage at the margins of lung lobes. In the whole-body infiltration group, the thoracic cavities of the fetus were flattened, lung cavities were small, and alveoli and bronchi were shrunken. In the whole-body infiltration group after intratracheal infusion of fetal rats, the fetal thoracic cavities were full, lung cavities were large, and alveoli and bronchi were relatively full. ConclusionThe lung infiltration after intratracheal infusion method for fetal rat lung tissue fixation outperforms direct lung infiltration, whole-body infiltration of fetal rats, and whole-body infiltration after intratracheal infusion of fetal rats in terms of preservation of the lung tissue's original morphology, paraffin sectioning, staining, and pathological observation and analysis. The embedding, sectioning, and staining processes are also simple and save consumables. Therefore, intratracheal infusion followed by lung infiltration method is recommended for fixation in histopathological observation of fetal rat lung tissue.

Objective:To study the results of detection of pulmonary nodules among military flying personnel and analyze the contributors to pulmonary nodules so as to provide data for early prevention and interventions.Methods:The physical examination data of 1 465 military flying personnel was retrospectively analyzed who had received the annual health checkup and undergone chest CT examinations at Lintong Rehabilitation and Recuperation Center. They were grouped by age (<40 years and ≥40 years), flying hour (<1 000 h and ≥1 000 h) and type of personnel [pilots and air support (technical) personnel]. The detection rates of pulmonary nodules among flying personnel were compared across groups, and a multivariate Logistic regression analysis was conducted to analyze the contributing factors to pulmonary nodules.Results:Among the 1 465 military flying personnel, 212 cases (14.47%) with pulmonary nodules were detected. A total of 230 pulmonary nodules were detected, including 35 pulmonary nodules (15.22%) in the left upper lung, 42 pulmonary nodules (18.26%) in the left lower lung, 52 pulmonary nodules (22.61%) in the right upper lung, 47 pulmonary nodules (20.43%) in the right middle lung, and 54 pulmonary nodules (23.48%) in the right lower lung. The detection rate of pulmonary nodules among military flying personnel in the ≥1 000 h group was higher than in the <1 000 h group, and the difference was statistically significant ( χ2=4.14, P=0.042). More pulmonary nodules were detected among military flying personnel who smoked than among those who did not, and the difference was statistically significant ( χ2=9.34, P=0.002). Age, types of personnel, body mass index, and complications with other lung diseases made no significant difference in the detection rate of pulmonary nodules (all P>0.05). Multivariate Logistic regression analysis showed that smoking was a risk factor for pulmonary nodules ( OR=1.692, 95% CI: 1.217-2.351). Conclusions:Among military flying personnel, pulmonary nodules are more likely to occur in the right lung. Smoking is an independent risk factor for pulmonary nodules, suggesting that routine chest CT screening should be carried out during the annual physical examinations of military flying personnel in order to exercise early interventions.

Objective:To establish a digital quality evaluation system for Salvia miltiorrhiza-Monascus fermentation products,screen critical quality markers,and provide methodological support for their intelligent quality control.Methods:Ultra-performance liquid chromatography coupled with quadrupole-orbitrap mass spectrometry(UPLC-Q-Orbitrap-MS)was employed to quantitatively analyze 34 bioactive components(e.g.,tanshinone Ⅱ A and alvianol-ic acid B)in 20 batches of fermentation products.The key markers were screened through hierarchical cluster anal-ysis and partial least squares discriminant analysis,and an intelligent discriminant model was constructed with sup-port vector machine machine learning algorithm to digitally analyze the characteristics of quality differences between batches.Results:Thirty-four common peaks were calibrated across all batches.Combined with partial least squares analysis,six key difference markers were further screened,including terpenoids such as isotanshinone Ⅱ A and tan-shinone Ⅱ A and phenolic acids such as salvianolic acid G.The support vector machine model can achieve 100％accuracy of origin discrimination by optimizing parameters jointly with genetic algorithm and grid search.Conclusion:This study developed a digital quality evaluation system for Salvia miltiorrhiza-Monascus fermentation products through a three-step analytical strategy("chemical feature exploration-marker screening-model valida-tion"),providing a transferable technical pathway for the intelligent transformation of traditional Chinese medicine quality control.

Objective:To explore the relationship between gut microbiota and giant cell arteritis (GCA), and to identifyits potential therapeutic strategies.Methods:Gut microbiota data were obtained from the MiBioGen consortium genome-wide association study (GWAS), and GCA data were obtained from the FinnGen consortium public GWAS. Causal associations between gut microbiota and GCA were assessed using two-sample Mendelian randomization (MR) analyses, including inverse-variance weighted (IVW), weighted median, MR-Egger regression, simple mode, and weighted mode methods. Heterogeneity and horizontal pleiotropy were evaluated, and false positive results were excluded by using the Benjamini-Hochberg (BH) method of multiple hypothesis testing. All analyses were completed using the TwoSampleMR and MRPRESSO software packages (version 4.3.0) in R language. The analysis of the intestinal flora data, followed by conducting network pharmacology analysis were carried out by Cytoscape 3.9.1 and perform molecular docking verification was performed with AutoDock Vina software.Results:IVW simulations revealed 13 gut microbiota taxa were associated with GCA, of which Lachnospiraceae was significantly negatively associated with GCA risk[nSNP=16, OR(95% CI)=0.32(0.16, 0.63), β=-1.15, Se=0.35, P=0.001, FDR<0.05], and there was no heterogeneity (Cochran′s Q test, Q=13.42, P=0.490) as well as horizontal pleiotropy ( P=0.370). Further literature search and computer simulation docking analysis showed that genistein binds to MMP2 with a binding energy of -43.1 kJ/mol. Conclusion:Lachnospiraceae in the gut microbiota was is negatively associated with GCA, and genistein may be able to regulate the abundance of Lachnospiraceae through the MMP2 target to treat GCA, providing a new therapeutic approach for giant cell arteritis.

BACKGROUND:The asymmetrical biomechanical environment of adolescent idiopathic scoliosis can lead to further wedge deformation of the vertebral body,which may affect cardiopulmonary function and compress nerves in severe cases.Adolescent idiopathic scoliosis with different degrees of scoliosis should be treated with exercise,bracing,and surgery.However,the mechanical mechanism of selecting an orthopedic approach remains unclear due to the individual variability of patients.OBJECTIVE:To investigate the biomechanical mechanism of different orthopedic modalities for the treatment of adolescent idiopathic scoliosis to provide a basis for clinical selection of treatment modalities based on the spine model of adolescent idiopathic scoliosis patients.METHODS:Based on the CT images of an adolescent idiopathic scoliosis patient,a scoliosis model(C7-L5)was reconstructed in Mimics software in three dimensions,and lateral thrust force was applied at the T8/T9 thorax and vertical distraction force was applied over the C7 vertebra with the magnitude of 20,40,60,80,100,and 120 N.The intervertebral disc stress and vertebral displacement in concave and convex sides,and Cobb angle of the spine were analyzed under two orthopedic modalities.RESULTS AND CONCLUSION:(1)With lateral thrust,there was no significant change in the C7T1-T7T8 intervertebral disc.The concave and convex stress of T7T8-L4L5 segment decreased first and then increased with the increase of lateral thrust force.The correction effect of lateral thrust on the segment near T8T9 was obvious and weakened with the extension of the segment to the cephalic and caudal ends.At 120 N of lateral thrust,the thoracic Cobb angle changed from 53.2° to 32.5° and the lumbar Cobb angle changed from 50.2° to 43.9°.(2)With the vertical distraction,the thoracic intervertebral disc stresses first decreased and then increased,and all the lumbar disc stresses decreased.The C7 displacement was the most obvious,and the correction effect gradually diminished with the segment extended to the caudal end.At a vertical distraction force of 120 N,the thoracic Cobb angle changed from 53.2° to 39.4° and the lumbar Cobb angle changed from 50.2° to 47.6°.(3)It is concluded that both orthopedic modalities provide improvement in the degree of scoliosis,with the thoracic correction being greater than the lumbar correction.Also,the asymmetric stress distribution on the concave and convex sides is improved,which contributes to normal bone growth.A vertical distraction approach is appropriate for larger Cobb angles,and a lateral thrust approach is appropriate for smaller Cobb angles.The results of this study help to understand the mechanism of spinal orthosis and provide a theoretical basis for the choice of orthopedic approach.

Objective To measure and analyze anatomic parameters of resected distal femurs and proximal tibias in Kaschin-Beck disease(KBD)and osteoarthritic(OA)knees which fit for total knee arthroplasty(TKA),so as to provide basis for designing suitable knee prosthesis for KBD patients.Methods A total of 154 knees(75 KBD and 79 OA)fitting for TKA underwent three-dimensional reconstruction;resection of distal femurs and proximal tibias was simulated during TKA.We measured the distal femoral mediolateral(fML),lateral anteroposterior(fLAP),medial anteroposterior(fMAP),medial condylar width(fMCW),lateral condylar width(fLCW)and fML/fLAP aspect ratio,proximal tibial mediolateral(tML),middle anteroposterior(tAP),medial anteroposterior(tMAP),lateral anteroposterior(tLAP)dimension,and tML/tAP aspect ratio to compare the morphometric differences between KBD and OA knees.Results The measured anatomic parameters of resected distal femurs and proximal tibias in both male and female patients of KBD group were smaller than those of OA knees(P＜0.01).We also found that KBD group had larger distal femur fML/fLAP and proximal tibia tML/tAP aspect ratios than those of OA knees(P＜0.01).This indicated that under a given AP dimension,KBD knees need an oval-shaped prosthesis with a wider ML length and more spherical-shaped prosthesis with relatively narrow ML dimensions in OA knees.Conclusion The anatomy of distal femurs and proximal tibias shows significant differences in size and shape between KBD and OA knees,which provides theoretical basis for designing proper knee prosthesis for KBD patients.