AIM:To observe the changes of atrial fibrillation susceptibility,and the remodeling of atrial myo-cyte action potential,ultrarapid activation delayed rectifier potassium current(IKur)and transient outward potassium cur-rent(Ito)in elderly mice,and to explore the mechanism of atrial fibrillation from the single cell electrophysiological level.METHODS:The C57BL/6J mice were divided into old group(20 months old)and young group(4 months old).Atrial fi-brillation was induced by esophageal atrial pacing.The atrial myocytes were isolated,and action potential and ion currents were recorded with patch-clamp technique.The associated proteins were detected by Western blot technique.RE-SULTS:(1)Compared with young mice,the total incidence of atrial fibrillation was significantly increased in old mice(20.0%at 4 months old vs 60.0%at 20 months old,P<0.01).(2)The action potential duration of atrial myocytes in aged mice was shortened,and more significantly after stimulation.(3)The density of Ito and IKur in atrial myocytes of aged mice increased significantly,from(12.6±1.4)pA/pF to(21.7±1.1)pA/pF,and from(7.5±1.5)pA/pF to(13.3±2.1)pA/pF,respectively(P<0.01).After stimulation,the current increased more significantly,especially in older atrial cells.Compared with the young mice,the steady-state activation curve of Ito in the atrial myocytes of the aged mice shifted towards the depolarization,suggesting that activation of Ito channels in the aged mice increased at the same voltage stimula-tion.(4)Compared with young group,the expression of KV4.2(generating Ito)and KV1.5(generating IKur)proteins in the atrial tissue of the mice in old group was significantly increased,and the expression of caveolin-3 and end-binding protein 1(EB1)was up-regulated,suggesting that the increases in KV4.2 and KV1.5 total channel proteins and effective proteins in the cell membrane might contribute to the increase in the remodeling of potassium currents in the elderly atrial myo-cytes.CONCLUSION:The incidence of atrial fibrillation in elderly mice is significantly augmented,which may be related to the increases in Ito and IKur in atrial myocytes.The remodeling of potassium currents in elderly atrial myocytes is one of the electrophysiological bases leading to the shortening of action potential duration and the occurrence of atrial fibrillation.

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.

Spinal trauma, primarily caused by high-energy external forces, predominantly manifest as vertebral fracture and spinal cord injury. These conditions are characterized by spinal pain, restricted mobility, and sensory and autonomic dysfunction, significantly compromising patients′ quality of life and life expectancy. Current diagnostic and therapeutic practices for spinal fracture remain susceptible to subjective clinical experience, resulting in misdiagnosis, underdiagnosis, and imprecise surgical execution. Similarly, the therapeutic efficacy of spinal cord injury rehabilitation is frequently limited by a lack of personalized treatment protocols. The growing integration of artificial intelligence (AI) in medicine presents novel opportunities to overcome these obstacles. By excelling in image interpretation, data analytics, clinical decision support, and personalized rehabilitation planning, AI has emerged as a prominent focus of modern research. To this end, the authors reviewed the research progress in the application of AI in the diagnosis and treatment of spinal fracture and rehabilitation of spinal cord injury, providing a reference for AI-assisted precision diagnosis and treatment of vertebral fracture and rehabilitation of spinal cord injury.

Objective To investigate the application of offline solid-phase extraction-high performance liquid chromatography-tandem mass spectrometry for detecting four synthetic cannabinoids(5F-ADB,5F-MDMB-PICA,4F-MDMB-BUTINACA,and MDMB-4en-PINACA)and their marker metabolites in urban wastewater.Methods Samples were pre-treated using an Oasis PRiME HLB column(60 mg,3CC)and analyzed by ultra-high performance liquid chromatography-triple quadrupole tandem mass spectrometry.The mobile phases consisted of 0.02%formic acid-2 mmol/L ammonium formate aqueous solution and acetonitrile solution,with a WATERS ACQUITY UPLCHSS T3 column.Analysis was conducted in positive ionization mode of the ESI ion source,combining multiple reaction monitoring(MRM),information-dependent acquisition(IDA),and enhanced product ion(EPI)scanning modes for qualitative and quantitative analysis of the eight target compounds.Results Good linearity was observed for 4F-MDMB-BUTINACA-M,5F-ADB,5F-ADB-M,and 5F-MDMB-PICA in the concentration range of 1～250 ng/L;for MDMB-4en-PINACA in the range of 5～250 ng/L;and for 4F-MDMB-BUTINACA,5F-MDMB-PICA-M,and 4F-MDMB-BUTINACA-M in the range of 1～500 ng/L.The recovery rates of samples spiked with different concentrations of the eight target compounds ranged from 87.68%to 104.68%,with matrix effects between 88.61%and 112.78%.Both intra-day and inter-day precision were less than 5%.Conclusion The established method demonstrates good accuracy and reproducibility,making it suitable for qualitative and quantitative detection of four synthetic cannabinoids and their metabolites in urban wastewater.

Objective To analyze the global research literature on monkeypox from 2014 to 2024 through bibliometric analysis,and provide reference for monkeypox research in China.Methods Based on data from the Web of Science Core Collection database and utilizing the visualization analysis capabilities of VOSviewer software,we employed keyword co-occurrence analysis and national cooperative network analysis methods and examined the trends in monkeypox research publications,popular journals,high-yield institutions,international collaborations,and keywords.Results A total of 2 396 papers were published from 2014 to 2024,with a significant increase in publications after 2022.The United States had the highest number of publications(808 papers,accounting for 33.72%).The network of international scientific collaborations showed close cooperation between the United States and countries like the United Kingdom and Canada,frequent collaborations among developing countries such as China and India,and extensive cooperation among European countries like Italy and Spain,which also established partnerships with Brazil,Mexico,and others.Keywords co-occurrence clustering and essential science indicators(ESI)highly cited papers revealed that the monkeypox research hotspots after 2022 including the analysis of the virology,clinical,epidemiological characteristics of the global outbreak in 2022,uncovering the causes of the global outbreak and the differences from previous outbreaks.Studies on vaccines and antiviral drugs also gradually became focal points.Conclusion Since the outbreak of monkeypox in 2022,monkeypox research has developed rapidly.Papers focus on specific populations,and gradually shifting from virological,clinical and epidemiological characterization to the development of new drugs,vaccines,and clinical validation studies.

Objective To analyze the current status of malaria vaccine research from 2019 to 2024 by using bibliometric methods.Methods Based on the Web of Science core collection database,we used VOSviewer to conduct a visual analysis of the publishing trends,publishing journals,international cooperation status,institutions and research hotspots of malaria vaccine research.Results A total of 2 467 relevant articles were retrieved,and the annual number of publications showed a stable trend.The number of articles published by different countries/regions varied greatly,and the top effect was obvious.The United States published the most papers(1 032 articles,41.83%).The international cooperation network reflected the regional collaborative relationships in malaria vaccine research,predominantly involving the United States,the United Kingdom,Australia,India and China.Through keyword co-occurrence clustering,the current research hotspots in the field of malaria vaccines were basic research on key sites and mechanisms of potential vaccines,clinical research on new vaccines,epidemiological studies on the impact of malaria vaccines on malaria transmission,etc.Conclusion In recent years,malaria vaccine research has received sustained attention.The translation of clinical research on malaria vaccine was currently accelerating,and children and women were still the key groups of concern.

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.

Objective To investigate the antimicrobial resistance of clinical isolates from elderly patients(≥65 years)in major medical institutions across China.Methods Bacterial strains were isolated from elderly patients in 52 hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program during the period from 2015 to 2021.Antimicrobial susceptibility test was carried out by disk diffusion method and automated systems according to the same CHINET protocol.The data were interpreted in accordance with the breakpoints recommended by the Clinical and Laboratory Standards Institute(CLSI)in 2021.Results A total of 514 715 nonduplicate clinical isolates were collected from elderly patients in 52 hospitals from January 1,2015 to December 31,2021.The number of isolates accounted for 34.3％of the total number of clinical isolates from all patients.Overall,21.8％of the 514 715 strains were gram-positive bacteria,and 78.2％were gram-negative bacteria.Majority(90.9％)of the strains were isolated from inpatients.About 42.9％of the strains were isolated from respiratory specimens,and 22.9％were isolated from urine.More than half(60.7％)of the strains were isolated from male patients,and 39.3％isolated from females.About 51.1％of the strains were isolated from patients aged 65-＜75 years.The prevalence of methicillin-resistant strains(MRSA)was 38.8％in 32 190 strains of Staphylococcus aureus.No vancomycin-or linezolid-resistant strains were found.The resistance rate of E.faecalis to most antibiotics was significantly lower than that of Enterococcus faecium,but a few vancomycin-resistant strains(0.2％,1.5％)and linezolid-resistant strains(3.4％,0.3％)were found in E.faecalis and E.faecium.The prevalence of penicillin-susceptible S.pneumoniae(PSSP),penicillin-intermediate S.pneumoniae(PISP),and penicillin-resistant S.pneumoniae(PRSP)was 94.3％,4.0％,and 1.7％in nonmeningitis S.pneumoniae isolates.The resistance rates of Klebsiella spp.(Klebsiella pneumoniae 93.2％)to imipenem and meropenem were 20.9％and 22.3％,respectively.Other Enterobacterales species were highly sensitive to carbapenem antibiotics.Only 1.7％-7.8％of other Enterobacterales strains were resistant to carbapenems.The resistance rates of Acinetobacter spp.(Acinetobacter baumannii 90.6％)to imipenem and meropenem were 68.4％and 70.6％respectively,while 28.5％and 24.3％of P.aeruginosa strains were resistant to imipenem and meropenem,respectively.Conclusions The number of clinical isolates from elderly patients is increasing year by year,especially in the 65-＜75 age group.Respiratory tract isolates were more prevalent in male elderly patients,and urinary tract isolates were more prevalent in female elderly patients.Klebsiella isolates were increasingly resistant to multiple antimicrobial agents,especially carbapenems.Antimicrobial resistance surveillance is helpful for accurate empirical antimicrobial therapy in elderly patients.

Objective To investigate the ameliorative effects and mechanisms of six types of tea(green tea,cyan tea,red tea,white tea,black tea and yellow tea)on metabolic disorders in obesity mice induced by high-fat diet(HFD).Methods Four-week-old male C57BL/6J mice were randomly divided into 8 groups with 7 mice per group.An HFD-induced obese mouse model was established,and the mice in control group maintained on standard diet followed by intragastric administration of different teas for 5 weeks.The body weight,liver weight ratio,fasting blood glucose,and lipid profile of the mice were measured to assess glucose and lipid metabolism.Serum inflammatory factors including IL-6,tumor necrosis factor-alpha(TNF-α)and oxidative stress markers[malondialdehyde(MDA)and superoxide dismutase(SOD)were measured.Additionally,liver histopathology and the expression of key glycolipid metabolism-related genes,adenosine monophosphate-activated protein kinase(AMPK)and carnitine palmitoyltransferase 1(CPT-1),were analyzed to explore underlying mechanisms.Results Cyan tea significantly suppressed weight gain,demonstrating superior weight control.White tea markedly reduced fasting blood glucose levels and decreased the area under the curve of oral glucose tolerance test(OGTT)and insulin tolerance test(ITT),indicating synergistic improvements in glucose metabolism and insulin sensitivity.Yellow tea exhibited exceptional anti-inflammatory and antioxidant effects,reducing hepatic IL-6 and MDA while enhancing SOD activity.Green tea activated the lipid oxidation pathway by upregulating AMPK/CPT-1 expression.All kinds of tea significantly attenuated hepatic lipid droplet accumulation.Conclusion All six types of tea alleviated metabolic disorders by reducing hepatic fat content in obesity mice.However,different types of tea exert their unique effects on improving metabolic disorders through differential mechanisms such as glucose metabolism regulation,lipid oxidation,and anti-inflammatory and antioxidant actions.

To investigate the phenotype and genomic characterization of a mucoid-type Salmonella Saintpaul ST50 isolate from a urinary tract infection patient,promoting clinical diagnosis and treatment for urinary tract infections caused by Salmo-nella spp.Culture-based quantitative counts of midstream urine sample from the patient were conducted,and further biochemi-cal identification,mass spectrometry detection,serum agglutination test and antimicrobial susceptibility test(AST)were con-ducted on Salmonella isolate(2024JD5).Whole-genome sequencing(WGS)was performed on isolate 2024JD5 to predict sero-type,multilocus sequence type(MLST),resistance genes,and virulence genes.Two smooth-type of Salmonella Saintpaul ST50 were selected as comparative genomic reference strains from the Chinese local Salmonella genome database.The literature reviews of global Salmonella serotype of urinary tract infection were summarized.Specific serum agglutination confir-mation of isolate 2024JD5 failed due to characterization of the mucus type.The strain 2024JD5 was predicted as Salmonella Saintpaul(4,5,12:e,h:1,2)ST50 using WGS,and was resistant to ciprofloxacin,nalidixic acid,chloramphenicol and tetracy-cline with carrying aminoglycoside resistance genes aac(6')-Ⅰaa and aph(3)-Ⅱa,chloramphenicol resistance gene floR,tetra-cycline resistance gene tet,quinolone resistance gene qnrS1,and S83Y substitution in the gyrA gene was found in the quinolo-ne resistance determination region(QRDR).In addition,the strain 2024JD4 carried six types of non-plasmid-based mobile ge-netic elements and 144 virulence genes,including 71 secretion transporter genes and 58 fimbriae adhesion genes,respectively.Four types of fimbriae regulatory genes(csgB,csgC,fimW,fimY)were absent in comparison with smooth-type Salmonella Saintpaul.The literature reviews showed Salmonella Saintpaul was currently a rare Salmonella serotype in cases of urinary tract infections worldwide.Salmonella Saintpaul ST50 with mucoid-type is the pathogen of urinary tract infection with multi-drug resistant phenotypic and genotypic characteristics,and the high mucoid expression may be related to the compensatory mechanism of fimbriae regulatory genes absence in urinary tract colonization and adaptation.WGS combined with the Chinese local Salmonella genome database can effectively solve the diagnosis and biosafety assessments of rare Salmonella phenotypes.