Exercise fatigue is a complex physiological and psychological phenomenon that includes peripheral fatigue in the muscles and central fatigue in the brain. Peripheral fatigue refers to the loss of force caused at the distal end of the neuromuscular junction, whereas central fatigue involves decreased motor output from the primary motor cortex, which is associated with modulations at anatomical sites proximal to nerves that innervate skeletal muscle. The central regulatory failure reflects a progressive decline in the central nervous system’s capacity to recruit motor units during sustained physical activity. Emerging evidence highlights the critical involvement of central neurochemical regulation in fatigue development, particularly through neurotransmitter-mediated modulation. Alterations in neurotransmitter release and receptor activity could influence excitatory and inhibitory signal pathways, thus modulating the perception of fatigue and exercise performance. Increased serotonin (5-HT) could increase perception of effort and lethargy, reduce motor drive to continue exercising, and contribute to exercise fatigue. Decreased dopamine (DA) and noradrenaline (NE) neurotransmission can negatively impact arousal, mood, motivation, and reward mechanisms and impair exercise performance. Furthermore, the serotonergic and dopaminergic systems interact with each other; a low 5-HT/DA ratio enhances motor motivation and improves performance, and a high 5-HT/DA ratio heightens fatigue perception and leads to decreased performance. The expression and activity of neurotransmitter receptors would be changed during prolonged exercise to fatigue, affecting the transmission of nerve signals. Prolonged high-intensity exercise causes excess 5-HT to overflow from the synaptic cleft to the axonal initial segment and activates the 5-HT1A receptor, thereby inhibiting the action potential of motor neurons and affecting the recruitment of motor units. During exercise to fatigue, the DA secretion is decreased, which blocks the binding of DA to D1 receptor in the caudate putamen and inhibits the activation of the direct pathway of the basal ganglia to suppress movement, meanwhile the binding of DA to D2 receptor is restrained in the caudate putamen, which activates the indirect pathway of the basal ganglia to influence motivation. Furthermore, other neurotransmitters and their receptors, such as adenosine (ADO), glutamic acid (Glu), and γ‑aminobutyric acid (GABA) also play important roles in regulating neurotransmitter balance and fatigue. The occurrence of central fatigue is not the result of the action of a single neurotransmitter system, but a comprehensive manifestation of the interaction between multiple neurotransmitters. This review explores the important role of neurotransmitters and their receptors in central motor fatigue, reveals the dynamic changes of different neurotransmitters such as 5-HT, DA, NE, and ADO during exercise, and summarizes the mechanisms by which these neurotransmitters and their receptors regulate fatigue perception and exercise performance through complex interactions. Besides, this study presents pharmacological evidence that drugs such as agonists, antagonists, and reuptake inhibitors could affect exercise performance by regulating the metabolic changes of neurotransmitters. Recently, emerging interventions such as dietary bioactive components intake and transcranial electrical stimulation may provide new ideas and strategies for the prevention and alleviation of exercise fatigue by regulating neurotransmitter levels and receptor activity. Overall, this work offers new theoretical insights into the understanding of exercise central fatigue, and future research should further investigate the relationship between neurotransmitters and their receptors and exercise fatigue.

Aim To explore the core target,key com-ponents and mechanism of Tibetan medicine Rhodiola crenulata in improving cerebral microcirculation based on literature research,network pharmacology,molecu-lar docking and experimental verification.Methods The chemical components of Rhodiola were collected through literature and database,and the potential tar-gets of Rhodiola crenulata were predicted by reverse pharmacophore matching.The related targets of cere-bral microcirculation disorder were obtained and targets were mapping with Rhodiola crenulata.PPI network was constructed and the core targets were screened.The regulatory network of"herb-component-target-dis-ease"was constructed and key components were screened.GO and KEGG enrichment analysis were conducted,and a"Core target-Pathway-Biological Process"network was constructed.Finally,molecular docking validation was carried out,and RT-qPCR and Western blot were used for animal experiments to fur-ther confirm the results of network pharmacology analy-sis.Results A total of 76 active components of Rhodiola crenulata were obtained and corresponding to 285 targets.Altogether 1074 related targets related to cerebral microcirculation disorder were obtained.A-mong them,there were 97 common targets and the main core targets were 6.The key components were 6.The results of molecular docking showed that the bind-ing activity of three key components to the core target was greater than that of the core target protein and its original ligand.The result of RT-qPCR and Western blot demonstrated that Tibetan medicine Rhodiola cre-nulata could significantly reduce the expression of core target CASP3 and AKT1(P＜0.01).Conclusions Tibetan medicine Rhodiola crenulata can improve the cerebral microcirculation disorder through multi compo-nents,multi targets and multi pathways.This study provides an experimental basis for clinical application of Tibetan medicine Rhodiola crenulata to treat cerebral microcirculation disorder.

Objective To investigate the distribution and antimicrobial resistance profiles of the common pathogens isolated from urine from 2015 to 2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods The bacterial strains were isolated from urine and identified routinely in 51 hospitals across China in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Antimicrobial susceptibility was determined by Kirby-Bauer method,automatic microbiological analysis system and E-test according to the unified protocol.Results A total of 261 893 nonduplicate strains were isolated from urine specimen from 2015 to 2021,of which gram-positive bacteria accounted for 23.8％(62 219/261 893),and gram-negative bacteria 76.2％(199 674/261 893).The most common species were E.coli(46.7％),E.faecium(10.4％),K.pneumoniae(9.8％),E.faecalis(8.7％),P.mirabilis(3.5％),P.aeruginosa(3.4％),SS.agalactiae(2.6％),and E.cloacae(2.1％).The strains were more frequently isolated from inpatients versus outpatients and emergency patients,from females versus males,and from adults versus children.The prevalence of ESBLs-producing strains in E.coli,K.pneumoniae and P.mirabilis was 53.2％,52.8％and 37.0％,respectively.The prevalence of carbapenem-resistant strains in E.coli,K.pneumoniae,P.aeruginosa and A.baumannii was 1.7％,18.5％,16.4％,and 40.3％,respectively.Lower than 10％of the E.faecalis isolates were resistant to ampicillin,nitrofurantoin,linezolid,vancomycin,teicoplanin and fosfomycin.More than 90％of the E.faecium isolates were ressitant to ampicillin,levofloxacin and erythromycin.The percentage of strains resistant to vancomycin,linezolid or teicoplanin was＜2％.The E.coli,K.pneumoniae,P.aeruginosa and A.baumannii strains isolated from ICU inpatients showed significantly higher resistance rates than the corresponding strains isolated from outpatients and non-ICU inpatients.Conclusions E.coli,Enterococcus and K.pneumoniae are the most common pathogens in urinary tract infection.The bacterial species and antimicrobial resistance of urinary isolates vary with different populations.More attention should be paid to antimicrobial resistance surveillance and reduce the irrational use of antimicrobial agents.

Objective To understand the distribution and changing resistance profiles of clinical isolates of Enterococcus in hospitals across China from 2015 to 2021.Methods Antimicrobial susceptibility testing was conducted for the clinical isolates of Enterococcus according to the unified protocol of CHINET program by automated systems,Kirby-Bauer method,or E-test strip.The results were interpreted according to the Clinical & Laboratory Standards Institute(CLSI)breakpoints in 2021.WHONET 5.6 software was used for statistical analysis.Results A total of 124 565 strains of Enterococcus were isolated during the 7-year period,mainly including Enterococcus faecalis(50.7％)and Enterococcus faecalis(41.5％).The strains were mainly isolated from urinary tract specimens(46.9％±2.6％),and primarily from the patients in the department of internal medicine,surgery and ICU.E.faecium and E.faecalis strains showed low level resistance rate to vancomycin,teicoplanin and linezolid(≤3.6％).The prevalence of vancomycin-resistant E.faecalis and E.faecium was 0.1％and 1.3％,respectively.The prevalence of linezolid-resistant E.faecalis increased from 0.7％in 2015 to 3.4％in 2021,while the prevalence of linezolid-resistant E.faecium was 0.3％.Conclusions The clinical isolates of Enterococcus were still highly susceptible to vancomycin,teicoplanin,and linezolid,evidenced by a low resistance rate.However,the prevalence of linezolid-resistant E.faecalis was increasing during the 7-year period.It is necessary to strengthen antimicrobial resistance surveillance to effectively identify the emergence of antibiotic-resistant bacteria and curb the spread of resistant pathogens.

Objective To examine the changing antimicrobial resistance profile of Enterobacter spp.isolates in 53 hospitals across China from 2015 t0 2021.Methods The clinical isolates of Enterobacter spp.were collected from 53 hospitals across China during 2015-2021 and tested for antimicrobial susceptibility using Kirby-Bauer method or automated testing systems according to the CHINET unified protocol.The results were interpreted according to the breakpoints issued by the Clinical & Laboratory Standards Institute(CLSI)in 2021(M100 31st edition)and analyzed with WHONET 5.6 software.Results A total of 37 966 Enterobacter strains were isolated from 2015 to 2021.The proportion of Enterobacter isolates among all clinical isolates showed a fluctuating trend over the 7-year period,overall 2.5％in all clinical isolates amd 5.7％in Enterobacterale strains.The most frequently isolated Enterobacter species was Enterobacter cloacae,accounting for 93.7％(35 571/37 966).The strains were mainly isolated from respiratory specimens(44.4±4.6)％,followed by secretions/pus(16.4±2.3)％and urine(16.0±0.9)％.The strains from respiratory samples decreased slightly,while those from sterile body fluids increased over the 7-year period.The Enterobacter strains were mainly isolated from inpatients(92.9％),and only(7.1±0.8)％of the strains were isolated from outpatients and emergency patients.The patients in surgical wards contributed the highest number of isolates(24.4±2.9)％compared to the inpatients in any other departement.Overall,≤ 7.9％of the E.cloacae strains were resistant to amikacin,tigecycline,polymyxin B,imipenem or meropenem,while ≤5.6％of the Enterobacter asburiae strains were resistant to these antimicrobial agents.E.asburiae showed higher resistance rate to polymyxin B than E.cloacae(19.7％vs 3.9％).Overall,≤8.1％of the Enterobacter gergoviae strains were resistant to tigecycline,amikacin,meropenem,or imipenem,while 10.5％of these strains were resistant to polycolistin B.The overall prevalence of carbapenem-resistant Enterobacter was 10.0％over the 7-year period,but showing an upward trend.The resistance profiles of Enterobacter isolates varied with the department from which they were isolated and whether the patient is an adult or a child.The prevalence of carbapenem-resistant E.cloacae was the highest in the E.cloacae isolates from ICU patients.Conclusions The results of the CHINET Antimicrobial Resistance Surveillance Program indicate that the proportion of Enterobacter strains in all clinical isolates fluctuates slightly over the 7-year period from 2015 to 2021.The Enterobacter strains showed increasing resistance to multiple antimicrobial drugs,especially carbapenems over the 7-year period.

Objective To understand the changing distribution and antimicrobial resistance profiles of Klebsiella strains in 52 hospitals across China in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Methods Antimicrobial susceptibility testing was carried out according to the unified CHINET protocol.The susceptibility results were interpreted according to the breakpoints in the Clinical & Laboratory Standards Institute(CLSI)M100 document.Results A total of 241,549 nonduplicate Klebsiella strains were isolated from 2015 to 2021,including Klebsiella pneumoniae(88.0％),Klebsiella aerogenes(5.8％),Klebsiella oxytoca(5.7％),and other Klebsiella species(0.6％).Klebsiella strains were mainly isolated from respiratory tract(48.49±5.32)％.Internal medicine(22.79±3.28)％,surgery(17.98±3.10)％,and ICU(14.03±1.39)％were the top 3 departments where Klebsiella strains were most frequently isolated.K.pneumoniae isolates showed higher resistance rate to most antimicrobial agents compared to other Klebsiella species.Klebsiella isolates maintained low resistance rates to tigecycline and polymyxin B.ESBLs-producing K.pneumoniae and K.oxytoca strains showed higher resistance rates to all the antimicrobial agents tested compared to the corresponding ESBLs-nonproducing strains.The K.pneumoniae and carbapenem-resistant K.pneumoniae(CRKP)strains isolated from ICU patients demonstrated higher resistance rates to majority of the antimicrobial agents tested than the strains isolated from non-ICU patients.The CRKP strains isolated from adult patients had higher resistance rates to most of the antimicrobial agents tested than the corresponding CRKP strains isolated from paediatric patients.Conclusions The prevalence of carbapenem-resistant strains in Klebsiella isolates increased greatly from 2015 to 2021.However,the Klebsiella isolates remained highly susceptible to tigecycline and polymyxin B.Antimicrobial resistance surveillance should still be strengthened for Klebsiella strains.

Objective To investigate the changing distribution and antibiotic resistance profiles of clinical isolates of Staphylococcus in hospitals across China from 2015 to 2021.Methods Antimicrobial susceptibility testing was conducted for the clinical isolates of Staphylococcus according to the unified protocol of CHINET(China Antimicrobial Surveillance Network)using disk diffusion method and commercial automated systems.The CHINET antimicrobial resistance surveillance data from 2015 to 2021 were interpreted according to the 2021 CLSI breakpoints and analyzed using WHONET 5.6.Results During the period from 2015 to 2021,a total of 204,771 nonduplicate strains of Staphylococcus were isolated,including 136,731(66.8％)strains of Staphylococcus aureus and 68,040(33.2％)strains of coagulase-negative Staphylococcus(CNS).The proportions of S.aureus isolates and CNS isolates did not show significant change.S.aureus strains were mainly isolated from respiratory specimens(38.9±5.1)％,wound,pus and secretions(33.6±4.2)％,and blood(11.9±1.5)％.The CNS strains were predominantly isolated from blood(73.6±4.2)％,cerebrospinal fluid(12.1±2.5)％,and pleural effusion and ascites(8.4±2.1)％.S.aureus strains were mainly isolated from the patients in ICU(17.0±7.3)％,outpatient and emergency(11.6±1.7)％,and department of surgery(11.2±0.9)％,whereas CNS strains were primarily isolated from the patients in ICU(32.2±9.7)％,outpatient and emergency(12.8±4.7)％,and department of internal medicine(11.2±1.9)％.The prevalence of methicillin-resistant strains was 32.9％in S.aureus(MRSA)and 74.1％in CNS(MRCNS).Over the 7-year period,the prevalence of MRSA decreased from 42.1％to 29.2％,and the prevalence of MRCNS decreased from 82.1％to 68.2％.MRSA showed higher resistance rates to all the antimicrobial agents tested except trimethoprim-sulfamethoxazole than methicillin-susceptible S.aureus(MSSA).Over the 7-year period,MRSA strains showed decreasing resistance rates to gentamicin,rifampicin,and levofloxacin,MRCNS showed decreasing resistance rates to gentamicin,erythromycin,rifampicin,and trimethoprim-sulfamethoxazole,but increasing resistance rate to levofloxacin.No vancomycin-resistant strains were detected.The prevalence of linezolid-resistant MRCNS increased from 0.2％to 2.3％over the 7-year period.Conclusions Staphylococcus remains the major pathogen among gram-positive bacteria.MRSA and MRCNS were still the principal antibiotic-resistant gram-positive bacteria.No S.aureus isolates were found resistant to vancomycin or linezolid,but linezolid-resistant strains have been detected in MRCNS isolates,which is an issue of concern.

Objective:To preliminarily investigate the applicability of a poliovirus pseudovirus-based neutralization assay in evaluating the immunogenicity of recombinant poliovirus vaccines and their in vivo potency in rats. Methods:Serum samples from rats immunized with recombinant poliovirus vaccines were tested using both the pseudovirus neutralization assay and the live-virus neutralization assay with Sabin strain. The consistency and correlation of the two methods were analyzed using the Kappa test and Spearman′s rank correlation.Results:For the neutralizing antibodies against typeⅠ, Ⅱ, and Ⅲ polioviruses, the Kappa values for consistency analysis of the two methods were 0.914, 1.000, and 0.751, respectively ( P<0.001), and the correlation coefficients ( R values) were 0.833, 0.927, and 0.859, respectively ( P<0.001). Conclusions:The test results of the two methods are consistent and show a good correlation, indicating that the pseudovirus neutralization assay can be applied to evaluating the immunogenicity of poliovirus vaccines and also can be used in rat potency tests.

Objective To understand the application of skin disinfectant in neonatal intensive care units(NICUs)nationwide.Methods From April to May 2023,application of skin disinfectant in 93 NICUs nationwide was sur-veyed with convenience sampling method by a self-designed questionnaire.Questionnaire contents included types of disinfectant,disinfection tools,cleaning and disinfection frequency,disinfectant drying status,removal of disinfec-tant,and adverse reactions caused by disinfectant.Results A total of 93 nursing units in 71 medical institutions from 25 provinces/municipalities were included in this study.In NICUs,three most commonly used disinfectants were ethanol(79.57％),iodophor(74.19％),and anerdian(62.37％).In nursing units for neonates＜2 months of age,chlorhexidine was prohibited in 28 units(30.11％),used with caution in 23 units(24.73％),allowed in 9 units(9.68％),and there was no unified requirement in 33 units(35.48％).When using ethanol,staff only wiped once in 13(17.57％)nursing units.In some nursing units,there was no unified requirements on the wiping fre-quency of disinfectant.As for the removal of residual iodine,saline was used in 29(42.03％)nursing units,ethanol in 8(11.59％),and 19(27.54％)did not have unified requirements.The adverse reactions of disinfectant mainly included rash and contact dermatitis.Disinfectants that caused adverse reactions included ethanol,iodophor,aner-dian,and chlorhexidine.Conclusion In clinical practice,unified standards for the use of neonatal skin disinfectant remain absent.Selection and use of neonatal skin disinfectant vary considerably.Neonatal skin disinfectants have common adverse reactions.It is necessary to strengthen the training of health care workers on the standardized use of disinfectant,as well as carry out large-scale and rigorous randomized controlled trial designs to provide scientific basis for the correct selection of disinfectant.

Objective To observe the clinical efficacy and safety of esketamine injection combined with sufentanil injection for patient-controlled intravenous analgesia(PCIA)after fracture surgery in children.Methods Children scheduled for elective limb fracture incision and internal fixation were randomly divided into control group and treatment group.The control group was given 2 μg·kg-1 sufentanil for PCIA;the treatment group was given 1.0 mg·kg-1 esketamine combined with 1.5 μg·kg-1 sufentanil for PCIA.Background dose of 2 groups:2 mL·h-1,single dose of 2 mL each time,locking time of 15 min,total volume of 100 mL.The facial expression,leg movement,mobility,crying,consolability scale(FLACC)scores and Ramsay sedation scores,analgesic drug consumption and PCIA compression times within 48 h after operation,and adverse drug reactions were compared between the two groups at different time points after operation.Results Forty subjects enrolled in the treatment group,1 dropped out,and 39 were finally included in the statistical analysis;40 subjects enrolled in the control group,2 dropped out,and 38 were finally included in the statistical analysis.After treatment,the FLACC scores of treatment group at 2,4,6,12,24 and 48 h after operation were(4.75±0.93),(2.50±0.97),(1.75±0.93),(2.06±1.18),(1.13±0.62)and(0.50±0.63)points,which in control group were(6.13±1.13),(3.80±1.21),(2.87±0.64),(3.47±1.13),(1.87±0.92)and(1.27±0.80)points,and there were significant differences in the two groups(all P＜0.05).The Ramsay sedation scores of treatment and control groups at 2 hours after operation were(2.25±0.45)and(1.47±0.52)points;the number of effective PCIA compressions within 24 hours was 4.25±3.94 and 8.13±5.71;the amount of analgesic drugs used within 24 hours after surgery was(52.38±9.11)and(61.47±12.82)mL;the amount of analgesic drugs used within 48 hours after surgery was(88.81±14.31)and(94.60±5.93)mL,respectively;and the differences were statistically significant(all P＜0.05).The adverse drug reactions of two groups were mainly dizziness,nausea and vomiting.The total incidences of adverse drug reactions in treatment and control groups were 53.85％and 84.21％with significant difference(P＜0.05).Conclusion Esketamine injection combined with sufentanil injection can reduce postoperative pain intensity,improve analgesic sedation effect and reduce the incidence of adverse reactions of analgesic pump after fracture surgery in children.