ObjectiveTo evaluate the effects of drinking chlorinated water on the intestinal flora of rats and mice and to explore differences in the intestinal microecological responses of model animals to chlorine stimulation in chlorinated drinking water systems. MethodsSix 8-week-old male SD rats and six 8-week-old male C57BL/6J mice were acclimated for 5 days. Subsequently, the drinking water for both rats and mice was changed from pure water to water containing free chlorine at a concentration of 25.4–32.4 nmol/L. The intervention lasted for 8 weeks, during which all animals were fed the same diet. Fecal samples were collected before the intervention (week 0, as the control group) and on the last day of week 3 and week 8 (as the chlorinated water group), and microbial composition was analyzed by 16S rRNA sequencing, including α diversity (Chao1 and Shannon indices), β diversity [principal component analysis (PCA)], and linear discriminant analysis effect size (LEfSe) analysis. ResultsAfter 3 weeks of intervention, α diversity of the intestinal flora in both rats and mice in the chlorinated water group was significantly lower than that in the control group (P < 0.01). After 8 weeks of intervention, no significant difference in α diversity was observed between rats in the chlorinated water group and those in the control group, whereas α diversity in mice remained significantly lower than that in the control group (P < 0.01). β diversity analysis showed significant alterations in microbial structure in the chlorinated water group. LEfSe analysis indicated that, compared with the control group, the abundances of Bacteroides and Ruminococcus were significantly reduced in the chlorinated water group, and microbial disturbance was more pronounced in mice [linear discriminant analysis (LDA) > 4.0], with a greater decrease in microbial diversity and a larger number of differentially abundant genera. ConclusionConsumption of chlorinated water can alter the diversity and structure of the intestinal flora in both rats and mice, with mice being more sensitive to this exposure. These findings suggest that the potential effects of chlorine on gut microecology should be considered in drinking water management and model selection for animal experiments.

Objective To investigate the differences in demographic characteristics,reproductive health status,and the distribution of pregnancy-related diseases between couples conceived via assisted reproductive technology(ART)and naturally conceived couples,and to analyze the impact of ART treatment on the incidence of preterm birth(PTB)in singleton and twin and multiple pregnancies.Methods We conducted a retrospective analysis of the maternal and infant cohort data of Jing'an District from 2013 to 2020.Based on the conception method,the subjects were categorized into two groups:the ART group and the natural conception group.Chi-square test was applied to compare baseline characteristics and disease distributions differences between the two groups,and logistic regression models were used to evaluate the association between ART and the PTB risks.A causal mediation model was used to evaluate the mediating effect of twin and multiple pregnancy in the relationship between ART and PTB.Results A total of 117 717 parturients were included,6 265 in the ART group and 111 452 in the natural conception group.Compared with the natural conception group,couples in the ART group were significantly older and had a higher prevalence of reproductive system diseases.The incidences of diabetes and hypertensive disorders during pregnancy in ART parturient were 13.76%and 9.99%,respectively,which were significantly higher than 7.88%and 4.75%in the natural conception group(both P<0.001).The overall PTB rate in the ART group was 14.81%,higher than 5.35%in the natural conceptions group(P<0.001).The PTB rate in ART for singleton pregnancies in the ART group was 6.40%,higher than 4.83%in the natural conception group(P<0.001),while the PTB rate in ART for twin and multiple pregnancies in the ART group was 53.97%,lower than 60.42%in the natural conception group(P<0.05).Mediation analysis showed that 97.99%of the effect of ART on PTB was mediated by twin and multiple pregnancy,with ART increasing the PTB risk by 3.44 times through multiple pregnancy.Conclusion The overall PTB rate of ART recipients is higher than that of natural recipients,but ART does not increase the PTB risk in singleton and twin and multiple pregnancies.Twin and multiple pregnancy is the key mediating factor contributing to PTB in ART-conceived recipients.Compared with naturally conceived couples,ART conception couples own more advanced maternal age,and have higher risks of suffering gestational diabetes,gestational hypertension,and PTB.

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 observe the clinical efficacy of Yijinjing in the treatment of elderly sarcopenia and its effect on chro-nic inflammatory response in patients,and to explore the Yijinjing exercise prescription suitable for elderly patients with sarcopenia.METHODS A total of 120 elderly patients with sarcopenia admitted to the Department of Rehabilitation Medicine,Suzhou Hospital of Traditional Chinese Medicine from September 2022 to September 2024 were selected and randomly divided into a control group and a Yijinjing group,with 60 cases in each group.The control group received health education and dietary guidance,and the Yijinjing group received Yijinjing exercises on the basis of the intervention of the control group.The changes in skeletal muscle mass,upper and lower limb muscle strength,muscle thickness,muscle cross-sectional area,physical fitness and chronic inflammation level were observed in the two groups before and after the intervention.RESULTS After intervention,the skeletal muscle mass,grip strength,30 s sit-stand test times,rectus femoris thickness and cross-sectional area,vastus intermedius thickness,and physical fit-ness assessment of the patients in the Yijinjing group were significantly increased compared with those before treatment(P<0.05),and the indicators after intervention were higher than those in the control group(P<0.05);the serum TNF-α and IL-18 levels in the Yi-jinjing group were significantly decreased compared with those before treatment(P<0.05),and the indicators after intervention were lower than those in the control group(P<0.05);there was no statistically significant change in the biceps brachii thickness and serum IL-6 level in the Yijinjing group compared with those before treatment(P>0.05);there was no significant correlation between the bi-ceps brachii thickness and grip strength after Yijinjing intervention,r=0.139 8,P>0.05;there was a significant negative correlation between the TNF-α level and grip strength after Yijinjing intervention,r=-0.313 8,P<0.05.CONCLUSION Yijinjing exercises can improve muscle mass and strength in elderly patients with sarcopenia,and improve the physical fitness of patients,which may be related to improving the chronic inflammatory state of the body.

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 study the effects of arsenic exposure on neurological function including voluntary motor ability, anxiety, and short-term memory ability of rats, as well as its impact on the expression levels of synaptic function related genes such as neuropeptide 1 (NLGN1), glutamate receptor 2A (NR2A), and postsynaptic density protein 95 (PSD95).Methods:Forty 3-week-old male specific pathogen free (SPF) grade Wistar rats [weighing (453.97 ± 35.68) g] were selected and divided into four groups using a random number table: 0 (control group) and 2, 10, and 50 mg/L arsenic exposure groups, with 10 rats in each group. They were given deionized water and 2, 10, and 50 mg/L sodium arsenite solutions for 12 weeks, respectively. The open field experiment and Y-maze experiment were used to test the voluntary motor ability, anxiety, and short-term memory ability of rats. Nissl staining was used to observe the pathological damage of the hippocampus in the brain. Real time fluorescence quantitative PCR and Western blot were used to detect the mRNA and protein expression levels of NLGN1, NR2A, and PSD95 in the hippocampus, respectively.Results:The results of the open field experiment revealed that the horizontal movement distances of rats in the 2 and 10 mg/L arsenic exposure groups were reduced compared to the control group, the movement distances in the central area in the 2, 10, and 50 mg/L arsenic exposure groups were reduced compared to the control group, and the residence time in the central area in the 10 and 50 mg/L arsenic exposure groups was reduced compared to the control group ( P < 0.05). The results of Y-maze experiment showed that the retention time of new arms in rats of the 2 and 10 mg/L arsenic exposure groups was shorter than that in the control group ( P < 0.05). The pathological examination results of Nissl staining showed that the control group had abundant Nissl bodies in hippocampal tissues of the cytoplasm with intact neuronal structures, tightly arranged cells, appearing blue purple in color and clear visible nuclei. However, the number of Nissl bodies decreased, intercellular gaps increased, disordered arrangement increased, cytoplasmic staining was lighter, and nuclear shrinkage phenomenon increased in the hippocampal tissues of rats in the 2, 10 and 50 mg/L arsenic exposure groups. The real-time fluorescence quantitative PCR detection results showed that there was a statistically significant difference in the mRNA expression levels of NLGN1, NR2A, and PSD95 in the hippocampal tissues of the four groups ( F = 13.85, 44.94, 4.63, P < 0.05). The results of Western blot analysis showed that the protein expression levels of NLGN1 and NR2A in the hippocampal tissues of rats in the 10 and 50 mg/L arsenic exposure groups were lower than those in the control group (0.65 ± 0.07, 0.69 ± 0.03 vs 1.00 ± 0.04, 0.51 ± 0.11, 0.51 ± 0.13 vs 1.00 ± 0.07, P < 0.05), and the expression level of PSD95 in the hippocampal tissues of rats in the 50 mg/L arsenic exposure group was lower than that in the control group (0.51 ± 0.09 vs 1.00 ± 0.05, P < 0.05). Conclusion:Arsenic may affect synaptic function and cause neurological dysfunction in rats by adjusting the expression levels of NLGN1, NR2A, and PSD95.

Blood from a case of group B epidemic cerebrospinal meningitis identified in February 2024 in Ganzhou City,Jiangxi Province,and throat swabs from close contacts were collected for isolation and culture.The isolates were subjected to serogrouping,drug sensitivity testing,and whole genome sequencing and analysis,to provide a basis for epidemiological inves-tigation and clinical drug use.One strain of Neisseria meningitidis was isolated from the blood of the case and denoted group B.The MLST type was ST-7962,with no clonal group attribution.The phylogenetic tree showed that it was genetically close to the 1977 Shanghai carrier isolate(id-52231).Drug sensitivity results indicated that the strain was sensitive to 8 drugs:azithro-mycin,cefotaxime,minocycline,ceftriaxone,chloramphenicol,meropenem,rifampicin,and benzylpenicillin;resistant to cot-rimoxazole,levofloxacin,and ciprofloxacin;and showed an intermediate response to penicillin.This report describes the first case of ST-7962 group B meningoencephalitis found in Jiangxi Province.Monitoring of Neisseria meningitidis carriage,drug re-sistance,and molecular characteristics of strains in the healthy population in this region should be strengthened,to provide la-boratory support for the clinical use of medications,traceability,and control of the pathogen underlying meningoencephalitis infection.

Objective To design a phased array ultrasonic focusing control system based on sinusoidal signal excitation in order to avoid the introduction of high-frequency interference components into the ultrasonic transducer and improve the electronic focusing performance of phased array ultrasound.Methods The system designed mainly used the high-speed field programmable gate array(FPGA)chip combined with the high-speed digital to analog converter(DAC)to realize synchronous output and control of multi-channel sinusoidal signals.There were 8 sinusoidal excitation emission modules based on FPGA and DAC and one sinusoidal ultrasonic excitation control module based on ZYNQ MPSoC involved in the hardware part of the system,in which the emission modules generated multi-channel sinusoidal excitations and timing control of sinusoidal signals within the module and the control module was responsible for controlling the triggering timing between each sinusoidal excitation transmitter module.The system developed had its software designed with MATLAB App Designer to improve the human-computer interaction experience.Performance verification was carried out for the system by testing the output waveform,inter-channel delay error and focused sound field of each channel.Results The system developed achieved generation and timing control of 64-channel sinusoidal ultrasound excitations,with the output channel main frequency being 0.5 MHz,amplitude within 0 and±12.5 V and the inter-channel delay errors not higher than 26.0 ns;a focused sound field with a focal spot diameter of 4.2 mm(-3 dB)at a depth of 50 mm was obtained when the system was applied to driving a 64-array phased-array transducer.Conclusion The system designed is capable of realizing ultrasonic electron focusing under sinusoidal excitation,which helps to improve the focusing resolution of non-invasive and precise deep brain stimulation techniques relying on the accuracy of ultrasonic focusing such as transcranial magneto-acoustic stimulation(TMAS)and transcranial ultrasonic stimulation(TUS).[Chinese Medical Equipment Journal,2025,46(5):14-20]