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 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.

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.

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 clinical value of coefficient of variation of heart rate and blood pressure in rapid identification of children with suspected orthostatic intolerance(OI). Methods: This was a retrospective study. The medical records of 379 children with OI were collected, who were admitted to the Department of Pediatrics of Qilu Hospital of Shandong University from January 2015 to January 2020. Another 20 out-patient children without syncope or syncope aura were selected as control. According to the results of standing test and head-up tilt test (HUTT), all the patients with OI were divided into the following 4 groups: vasovagal syncope (VVS) group, postural tachycardia syndrome (POTS) group, POTS combined with VVS (POTS+VVS) group and HUTT negative group. Then, coefficient of variation of systolic pressure (SBP_CV), coefficient of variation of diastolic pressure (DBP_CV) and coefficient of variation of heart rate (HR_CV) in standing test and HUTT were calculated. Kruskal-Wallis test was used for comparison among the five groups, and Dunnett's T3 method for comparison between two groups. Paired t test was used to compare the coefficient of variation between supine and erect position and tilt position in each group. The predictive values of HR_CV,SBP_CV and DBP_CV for negative HUTT were evaluated by receiver operating characteristic (ROC) curve. Results: Among the 379 children, there were 79 in HUTT negative group, 208 in VVS group, 52 in POTS group, and 40 in POTS+VVS group. The SBP_CV of supine-erect position of the control group, HUTT negative group, VVS group, POTS group, POTS+VVS group were (3.8±1.0)%, (5.3±2.2)%, (6.6±3.4)%, (5.9±3.6)%, (6.9±2.8)%, respectively. Similarly, the SBP_CV of supine, erect and head-up tilt position were (4.5±0.8)%, (6.0±1.9)%, (7.1±2.6)%, (6.0±2.1)%, (7.3±2.5)%; the DBP_CV of supine-erect position were (7.3±1.2)%, (9.1±3.7)%, (9.1±4.9)%, (9.1±4.8)%, (11.6±4.6)%; the DBP_CV of supine, erect and tilt position were (7.4±1.1)%, (9.4±2.9)%, (10.1±3.8)%, (9.2±3.3)%, (11.0±4.7)%; the HR_CV of supine-erect position were (7.6±2.6)%, (12.9±3.7)%, (16.2±4.3)%, (21.2±5.9)%, (24.9±5.3)%; and the HR_CV of supine, erect and tilt position were (8.1±1.6)%, (10.1±2.7)%, (14.1±4.3)%, (15.6±3.7)%, (18.9±4.0)%, respectively. All the indexes showed significant differences among the five groups (χ²=21.91, 25.47, 19.82, 14.65, 104.52, 92.51, all P<0.05). ROC curve analysis showed that when the SBP_CV and HR_CV of supine-erect position reached 4.4% and 10.5%, the area under the curve of ROC were 0.713 and 0.877, the sensitivity of predicting negative HUTT were 58.2% and 78.5%, and the specificity were 80.0% and 95.0%, respectively. Conclusions: Coefficient of variation of heart rate and blood pressure may serve as potential diagnostic indexes in evaluating autonomic function of OI patients. SBP_CV ≥ 4.4% or HR_CV ≥ 10.5% of supine-erect position could be an indication of HUTT.
Blood Pressure ; Child ; Heart Rate ; Humans ; Orthostatic Intolerance/diagnosis* ; Postural Orthostatic Tachycardia Syndrome/diagnosis* ; Retrospective Studies ; Syncope, Vasovagal/diagnosis* ; Tilt-Table Test