Objective To propose an improved Bouc-Wen model to alleviate the nonlinear effect of the hysteresis displacement of piezoceramics and enhance the motion control accuracy of the nano-displacement platform.Methods Firstly,two fine-tuning parameters including the asymmetric term and the input bias term were added to the classical Bouc-Wen model to eliminate the deviation of the starting and ending positions of the hysteresis curve,so as to obtain an improved Bouc-Wen model simulating the hysteresis displacement characteristics of piezoceramics on the nano-displacement platform.Secondly,the parameters of the improved Bouc-Wen model were identified based on the particle swarm optimization algorithm,and an inverse feedforward structure was adopted to realize the linearized control of the output displacement.Finally,an experimental system was built to verify the linearized control effect of the improved Bouc-Wen model.Results The hysteresis curve of the improved Bouc-Wen model fitted the actual voltage-displacement curve of piezoceramics significantly better when compared with that of the traditional model,which had a 56%reduction in the fitting error and a 0.03 μm error between the desired and actual displacements during the linearized output control with a driving voltage of 0-60 V and a maximum travel of about 4 μm.Conclusion The improved Bouc-Wen model behaves well in hysteresis displacement fitting and linearized output control,and a new idea is provided for enhancing the motion control accuracy of the nano-displacement platform.[Chinese Medical Equipment Journal,2025,46(8):25-31]

Objective To propose an improved Bouc-Wen model to alleviate the nonlinear effect of the hysteresis displacement of piezoceramics and enhance the motion control accuracy of the nano-displacement platform.Methods Firstly,two fine-tuning parameters including the asymmetric term and the input bias term were added to the classical Bouc-Wen model to eliminate the deviation of the starting and ending positions of the hysteresis curve,so as to obtain an improved Bouc-Wen model simulating the hysteresis displacement characteristics of piezoceramics on the nano-displacement platform.Secondly,the parameters of the improved Bouc-Wen model were identified based on the particle swarm optimization algorithm,and an inverse feedforward structure was adopted to realize the linearized control of the output displacement.Finally,an experimental system was built to verify the linearized control effect of the improved Bouc-Wen model.Results The hysteresis curve of the improved Bouc-Wen model fitted the actual voltage-displacement curve of piezoceramics significantly better when compared with that of the traditional model,which had a 56%reduction in the fitting error and a 0.03 μm error between the desired and actual displacements during the linearized output control with a driving voltage of 0-60 V and a maximum travel of about 4 μm.Conclusion The improved Bouc-Wen model behaves well in hysteresis displacement fitting and linearized output control,and a new idea is provided for enhancing the motion control accuracy of the nano-displacement platform.[Chinese Medical Equipment Journal,2025,46(8):25-31]

This study was aimed at investigating the antimicrobial susceptibility and genomic characteristics of multidrug resistant diarrheagenic Escherichia coli isolated from human and food samples in Henan Province from 2017 to 2022.A total of 101 strains of multidrug resistant diarrheagenic E.coli were subjected to antimicrobial susceptibility testing with the broth di-lution method.Whole genome sequencing was performed to analyze the antimicrobial resistance genes,multilocus sequence typ-ing,and plasmid types.The sequencing data were used to construct a phylogenetic tree based on core genome single-nucleotide polymorphisms(cgSNPs).The isolates showed the highest resistance to ampicillin(87.1％),followed by tetracycline(79.2％)and nalidixic acid(64.4％).The resistance rate to cefotaxime was 38.6％.All 101 strains were classified into 60 STs,among which ST10,ST1491,and ST38 were dominant.Moreover,23 distinct plasmid replicons were identified,among which IncFIB was dominant.Diverse antimicrobial resistance genes(including quinolone,aminoglycoside,β-lactamase,and tetracycline)were identified.Insertion sequences(IS26,IS903B,and ISECP 1)were identified in upstream and downstream analysis of the gene context of the extended-spectrum β-lactamase bla CTX-M-14 and bla CTX-M-55 genes.In conclusion,multidrug resistant diarrhea-genic Escherichia coli isolated from clinical and food samples in Henan Province showed high genetic diversity and high antimi-crobial resistance.The dissemination of blaCTX-M carried by the strains was shown to be associated with the insertion sequence(IS).

[Abstract] Objective To establish an inflammation model by stimulating BV2 microglia by lipopolysaccharide, and to explore the regulation effect of ginsenoside Rg1 on inflammation by activating peroxisome proliferator activated receptor γ(PPARγ) receptor protein. Methods BV2 microglia were randomly divided into control group, model group, ginsenoside Rg1 group, rosiglitazone group and GW9662 group. The control group did not do any treatment, the model group was treated with 1 mg/ L lipopolysaccharide, and the other groups were treated with lipopolysaccharide added with 0. 4 mmol/ L ginsenoside Rg1, 10 μmol/ L rosiglitazone or 10 μmol/ L respectively. GW9662. The proliferation of BV2 microglia in each group was detected by CCK-8 method; PPAR-γ, phospho-NF-κB p65 (p-NF-κB p65), induced expression of inducible nitric oxide synthase(iNOS) and human arginase 1(ARG-1) proteins. ELISA was used to detect the inflammatory factors interleukin-1β(IL-1β), interleukin-6(IL-6), interleukin-8(IL-8) and the content of tumor necrosis factor-α (TNF-α). Results Compared with the control group, the cell proliferation rate in the model group was significantly increased, and the contents of IL-1β, IL-6, IL-8 and TNF-α increased significantly. The result of immunofluorescence and Western blotting showed that iNOS and p-NF-κB p65 increased significantly, and the positive expressions of PPARγ and ARG-1 decreased significantly(both P<0. 01). The expression level of TNF-α decreased, the positive expressions of iNOS and p-NF-κB p65 decreased significantly, and the positive expressions of PPARγ and ARG-1 increased significantly(all P<0. 01). Conclusion Ginsenoside Rg1 inhibits the inflammatory response of BV2 microglia after lipopolysaccharide stimulation, and its mechanism may be related to the regulation of PPARγ/ NF-κB pathway to promote the M2-type polarization of microglia.

Objective: To explore the effect of kynurenine pathway on the osteogenic differentiation of periodontal ligament stem cells (PDLSC). Methods: Unstimulated saliva samples were collected from 19 patients with periodontitis (periodontitis group) and 19 periodontally healthy individuals (health group) in Nanjing Stomatological Hospital, Affiliated Hospital of Medical School, Nanjing University from June to October of 2022. Contents of kynurenine and the metabolites in saliva samples were analyzed by ultra-performance liquid chromatography-tandem mass spectrometry. The expressions of indoleamine 2, 3-dioxygenase (IDO) and aryl hydrocarbon receptor (AhR) were further detected by immunohistochemistry in gingival tissues. The PDLSC used in this study were isolated from extracted teeth for orthodontic treatment in Nanjing Stomatological Hospital, Affiliated Hospital of Medical School, Nanjing University from July to November of 2022. Experiments were then conducted using the cells by incubating with (kynurenine group) or without kynurenine (control group) in vitro. Seven days later, alkaline phosphatase (ALP) staining and assays of ALP activity were performed. Real-time fluorescence quantitative PCR (RT-qPCR) was utilized to detect the expressions of osteogenic related genes ALP, osteocalcin (OCN), runt-related transcription factor 2 (RUNX2), collagen type-Ⅰ (COL-Ⅰ) as well as the kynurenine pathway-associated genes AhR, cytochrome P450 family (CYP) 1A1, CYP1B1. Western blotting was used to detect the expression levels of RUNX2, osteopontin (OPN) and AhR proteins on day 10 and alizarin red staining was performed to observe the formation of mineral nodules on day 21 in control group and kynurenine group. Results: Salivary concentrations of kynurenine [8.26 (0, 19.60) nmol/L] and kynurenic acid [11.4 (3.34, 13.52) nmol/L] were significantly higher in the periodontitis group than in the health group [0.75(0, 4.25) nmol/L, 1.92(1.34, 3.88) nmol/L] (Z=-2.84, P=0.004; Z=-3.61, P<0.001). The expression levels of IDO (18.33±2.22) and AhR (44.14±13.63) in gingival tissues of periodontitis patients were significantly higher than that of the health group (12.21±2.87, 15.39±5.14) (t=3.38, P=0.015; t=3.42, P=0.027). In vitro, the ALP activity of PDLSC in the kynurenine group (291.90±2.35) decreased significantly compared with the control group (329.30±19.29) (t=3.34, P=0.029). The mRNA expression levels of ALP, OCN and RUNX2 in the kynurenine group (0.43±0.12, 0.78±0.09, 0.66±0.10) were decreased compared with the control group (1.02±0.22, 1.00±0.11, 1.00±0.01) (t=4.71, P=0.003; t=3.23, P=0.018; t=6.73, P<0.001), while the levels of AhR and CYP1A1 were increased in the kynurenine group (1.43±0.07, 1.65±0.10) compared with those in the control group (1.01±0.12, 1.01±0.14) (t=5.23, P=0.006; t=6.59, P<0.001). No significant difference was observed in COL-Ⅰ and CYP1B1 mRNA levels between groups. The protein levels of OPN, RUNX2 (0.82±0.05, 0.87±0.03) were reduced and that of AhR (1.24±0.14) was increased in the kynurenine group compared with those in the control group (1.00±0.00, 1.00±0.00, 1.00±0.00) (t=6.79, P=0.003; t=7.95, P=0.001; t=3.04, P=0.039). Conclusions: Over-activated kynurenine pathway in periodontitis patients can promote upregulation of AhR and suppress the osteogenic differentiation of PDLSC.

Objective To investigate the Gram-positive coccus resistance in nationwide's tertiary hospitals and understand the trend of antimicrobial resistance.Methods All the clinical isolates were collected from 19 hospitals and the minimal inhibitory concentrations(MICs)were tested using agar/broth dilution method recommended.Results A total of 1 974 pathogenic Gram-positive coccus from 19 tertiary hospitals in 19 cities nationwide over the period from July 2021 to June 2022 were studied.Based on the MIC results,the prevalence of methicillin resistant Stapylococcus aureus(MRSA)and methicillin resistant Stapylococcus epidermidis(MRSE)were 36.4％and 79.9％respectively.No vancomycin insensitivity Staphylococcus was detected.Staphylococcus aureus were 100％susceptibility to linezolid and teicoplanin.Antibiotic resistance rate of Enterococcus faecalis and Enterococcus faecium to ampicillin were 3.1％and 92.9％.The detectation rate of vancomycin resistant Enterococcus(VRE)was 1.6％.Nonsusceptibility rate of Enterococcus faecalis to linezolid was 32.2％,two consecutive monitoring rises and nonsusceptibility rate of Enterococcus faecium(12.5％)was also significantly increased.The prevalence of penicillin non-susceptible Streptococcus pneumoniae(PNSSP)was 0.8％based on non-meningitis and parenteral administration criterion,decrease of nearly 30 percentage points from the previous surveillance.While for cases of oral penicillin,the rate was 71.8％,showing similar to last time.The results indicated that the number of strains with higher MIC value of penicillin(MIC ≥4 mg·L-1)decreased significantly.There were no significant differences of resistance rates of Stapylococcus aureus,Stapylococcus epidermidis,Enterococcus faecalis,Enterococcus faecium and Streptococcus pneumoniae among various groups such as different department,age,or specimen source.Conclusion VRE detection ratio stablized at a relatively low level.The number of Streptococcus pneumoniae with higher MIC value of penicillin decreased significantly compared with the previous monitoring.The increase of linezolidin-insensitive Enterococcus was noteworthy.

Objective To investigate the Gram-negative bacteria resistance in nationwide's tertiary hospitals and understand the trend of antimicrobial resistance.Method All the clinical isolates were collected from 19 hospitals and the minimal inhibitory concentrations(MICs)were tested using agar/broth dilution method recommended.Results A total of 4 066 pathogenic isolates from 19 tertiary hospitals in 19 cities nationwide over the period from July 2021 to June 2022 were studied.Based on the MIC results,Escherichia coli and Klebsiella pneumoniae showed extended spectrum β-lactamase(ESBLs)phenotype rates of 55.0％and 21.0％,respectively,ESBLs phenotype rate of Klebsiella pneumoniae keep going down.The ratios of carbapenems resistance Klebsiella pneumoniae increased by 5 percentage points compared with the previous monitoring.Carbapenems,moxalactam,sitafloxacin,β-lactam combination agents,fosfomycin trometamol,and amikacin displayed desirable antibacterial activity against Enterbacterales,susceptibal rates were above 75％.In addition,tigacycline,omacycline,colistin and fluoxefin maintained good antibacterial activity against their respective effective bacteria/species,and the bacterial sensitivity rates by more than 80％.Resistance rates of Pseudomonas aeruginosa and Acinetobacter baumannnii to imipenem were 26.3％and 72.1％and multidrug-resistant(MDR)detection rates were 41.1％and 77.3％,extensively drug-resistant(XDR)were 12.0％and 71.8％,respectively.Comparison of drug resistance rates from different wards,ages and specimen sources indicated that the proportion of resistance in Klebsiella pneumoniae and Acinetobacter baumannii isolated from intensive care unit(ICU)were significantly higher than non-ICU.Carbapenem resistance rates of Klebsiella pneumoniae isolated from ICU were more than 35％.Resistance rates of Haemophilus influenzae isolated in children to β-lactam,macrolide,clindamycin and ESBLs detection rate in Klebsiella pneumoniae isolated from children were more than those from adults and the old people,so bacterial resistance in children is an important problem in China.Conclusion ESBLs detection rate of Escherichia coli increased slightly after years of continuous decline.The proportion of carbapenem resistant Pseudomonas aeruginosa was stable,but the resistance rate of Klebsiella pneumoniae and Acinetobacter baumannii to carbapenems was still increased,which should be paid more attention.

This paper focused on the research progress of the assessment methods of carers′ fall concern for the elderly. The content of this review included the definition of carers′ fall concern, and the advantages and disadvantages of various assessment method of carers′ fall concern for the caregivers to the elderly, such as qualitative interviews, questionnaires, and scales. Through this review, the authors hoped to provide a reference for selecting or developing a localized carers′ fall concern assessment tool.

Objective: To investigate the incidence and trend of short-term outcomes among preterm infants born <34 weeks' gestation. Methods: A secondary analysis of data from the standardized database established by a multicenter cluster-randomized controlled study "reduction of infection in neonatal intensive care units (NICU) using the evidence-based practice for improving quality (REIN-EPIQ) study". This study was conducted in 25 tertiary NICU. A total of 27 192 infants with gestational age <34 weeks at birth and admitted to NICU within the first 7 days of life from May 2015 to April 2018 were enrolled. Infants with severe congenital malformation were excluded. Descriptive analyses were used to describe the mortality and major morbidities of preterm infants by gestational age groups and different admission year groups. Cochran-Armitage test and Jonckheere-Terpstra test were used to analyze the trend of incidences of mortality and morbidities in 3 study-years. Multiple Logistic regression model was constructed to analyze the differences of outcomes in 3 study-years adjusting for confounders. Results: A total of 27 192 preterm infants were enrolled with gestational age of (31.3±2.0) weeks at birth and weight of (1 617±415) g at birth. Overall, 9.5% (2 594/27 192) of infants were discharged against medical advice, and the overall mortality rate was 10.7% (2 907/27 192). Mortality for infants who received complete care was 4.7% (1 147/24 598), and mortality or any major morbidity was 26.2% (6 452/24 598). The incidences of moderate to severe bronchopulmonary dysplasia, sepsis, severe intraventricular hemorrhage or periventricular leukomalacia, proven necrotizing enterocolitis, and severe retinopathy of prematurity were 16.0% (4 342/27 192), 11.9% (3 225/27 192), 6.8% (1 641/24 206), 3.6% (939/25 762) and 1.5% (214/13 868), respectively. There was a decreasing of the overall mortality (P<0.001) during the 3 years. Also, the incidences for sepsis and severe retinopathy of prematurity both decreased (both P<0.001). However, there were no significant differences in the major morbidity in preterm infants who received complete care during the 3-year study period (P=0.230). After adjusting for confounders, infants admitted during the third study year showed significantly lower risk of overall mortality (adjust OR=0.62, 95%CI 0.55-0.69, P<0.001), mortality or major morbidity, moderate to severe bronchopulmonary dysplasia, sepsis and severe retinopathy of prematurity, compared to those admitted in the first study year (all P<0.05). Conclusions: From 2015 to 2018, the mortality and major morbidities among preterm infants in Chinese NICU decreased, but there is still space for further efforts. Further targeted quality improvement is needed to improve the overall outcome of preterm infants.
Bronchopulmonary Dysplasia/epidemiology* ; Gestational Age ; Humans ; Infant ; Infant Mortality/trends* ; Infant, Newborn ; Infant, Premature ; Infant, Premature, Diseases/epidemiology* ; Patient Discharge ; Retinopathy of Prematurity/epidemiology* ; Sepsis/epidemiology*