Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in healthcare facilities in major regions of China in 2023.Methods Clinical isolates collected from 73 hospitals across China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2023 Clinical & Laboratory Standards Institute (CLSI) breakpoints.Results A total of 445199 clinical isolates were collected in 2023,of which 29.0％ were gram-positive and 71.0％ were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species (excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi) (MRSA,MRSE and MRCNS) was 29.6％,81.9％ and 78.5％,respectively.Methicillin-resistant strains showed significantly higher resistance rates to most antimicrobial agents than methicillin-susceptible strains (MSSA,MSSE and MSCNS).Overall,92.9％ of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 91.4％ of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis had significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 93.1％ in the isolates from children and and 95.9％ in the isolates from adults.The resistance rate to carbapenems was lower than 15.0％ for most Enterobacterales species except for Klebsiella,22.5％ and 23.6％ of which were resistant to imipenem and meropenem,respectively .Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.6％ to 10.0％.The resistance rate to imipenem and meropenem was 21.9％ and 17.4％ for Pseudomonas aeruginosa,respectively,and 67.5％ and 68.1％ for Acinetobacter baumannii,respectively.Conclusions Increasing resistance to the commonly used antimicrobial agents is still observed in clinical bacterial isolates.However,the prevalence of important crabapenem-resistant organisms such as crabapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a slightly decreasing trend.This finding suggests that strengthening bacterial resistance surveillance and multidisciplinary linkage are important for preventing the occurrence and development of bacterial resistance.

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in healthcare facilities in major regions of China in 2023.Methods Clinical isolates collected from 73 hospitals across China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2023 Clinical & Laboratory Standards Institute (CLSI) breakpoints.Results A total of 445199 clinical isolates were collected in 2023,of which 29.0％ were gram-positive and 71.0％ were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species (excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi) (MRSA,MRSE and MRCNS) was 29.6％,81.9％ and 78.5％,respectively.Methicillin-resistant strains showed significantly higher resistance rates to most antimicrobial agents than methicillin-susceptible strains (MSSA,MSSE and MSCNS).Overall,92.9％ of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 91.4％ of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis had significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 93.1％ in the isolates from children and and 95.9％ in the isolates from adults.The resistance rate to carbapenems was lower than 15.0％ for most Enterobacterales species except for Klebsiella,22.5％ and 23.6％ of which were resistant to imipenem and meropenem,respectively .Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.6％ to 10.0％.The resistance rate to imipenem and meropenem was 21.9％ and 17.4％ for Pseudomonas aeruginosa,respectively,and 67.5％ and 68.1％ for Acinetobacter baumannii,respectively.Conclusions Increasing resistance to the commonly used antimicrobial agents is still observed in clinical bacterial isolates.However,the prevalence of important crabapenem-resistant organisms such as crabapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a slightly decreasing trend.This finding suggests that strengthening bacterial resistance surveillance and multidisciplinary linkage are important for preventing the occurrence and development of bacterial resistance.

Objective To propose a human-machine coupling dynamics modeling method based on virtual muscles, so as to quantitatively analyze the characteristics of human-computer interaction force and muscle activation of the musculoskeletal system. Methods First, in the gait experiment of wearing exoskeleton, the human motion capture system and self-developed mechanical monitoring device were used to obtain the wearer’s walking dynamics, electromyography (EMG) signals, exoskeleton drive status and local human-computer interaction information. The human-machine coupling model was established in modeling environment of the bone system, and the gait experiment data and the exoskeleton joint torques were used as driving information of the coupling model to perform inverse mechanical calculations. Finally, by adjusting strength and stiffness parameters of the virtual muscles, the real data of the model was compared with the experimental test result, to quantitatively evaluate effectiveness of the human-machine coupling model of the lower extremity exoskeleton. Results The normal interaction force calculated by inverse dynamics of the coupled model and the activation of lower limb muscles had a good consistency in response curve trend compared with measurement results of the gait experiment, and the interaction force results had a high degree of correlation (r=0.931, P<0.01), the root mean square error was small, and the peak error of lower limb muscle activation was lower than 5%. Conclusions The human-machine coupling model proposed in this study can effectively calculate the interaction force between human and exoskeleton. The establishment of the coupling model provides a theoretical basis for verification and iteration of the exoskeleton structure optimization and control algorithm, as well as performance evaluation on mobility assistance effects of the exoskeleton.

Objective To explore the correlation between serum hepatitis C virus (HCV)-RNA level with cholinesterase (CHE), albumin (ALB) and prealbumin (PA) in patients with hepatitis C, and provide the references for the early diagnosis and the prognosis monitoring of hepatitis C. Methods Four hundred and fifty-five patients with hepatitis C were selected. The serum level of HCV-RNA was determined by quantitative real-time polymerase chain reaction (real-time PCR), and serum levels of CHE, ALB and PA were detected using the automatic biochemistry analyzer. The patients were divided into 6 group according to the result of HCV-RNA level:HCV-RNA<103 kU/L group (group A, 52 cases), 103 kU/L≤HCV-RNA<104 kU/L group (group B, 77 cases), 104 kU/L≤HCV-RNA<105 kU/L group (group C, 81 cases), 105 kU/L≤HCV-RNA<106 kU/L group (group D, 92 cases), 106 kU/L≤HCV-RNA<107 kU/L group (group E, 87 cases) and HCV-RNA≥107 kU/L group (group F, 66 cases). Moreover, the patients were divided into 3 groups according to the result of serum CHE: CHE normal group (> 5000 U/L, 321 cases), CHE mild abnormal group (4000- 5000 U/L, 56 cases) and CHE abnormal group (<4000 U/L, 78 cases). Results With the rising level of serum HCV-RNA from group A to group F, the serum levels of CHE, ALB and PA were all gradually decreased in hepatitis C patients, CHE: (7288 ± 2817), (6316 ± 2341), (6103 ± 2596), (5208 ± 2222), (4282 ± 2173) and (3905 ± 1378) U/L; ALB: (46.3 ± 9.9), (44.0 ± 8.4), (43.1 ± 7.6), (42.6 ± 7.1), (41.1 ± 5.4) and (39.3 ±5.1) g/L;PA:(212.1 ± 67.8), (179.9 ± 72.8), (163.4 ± 57.5), (137.4 ± 60.3), (120.6 ± 45.0) and (112.5 ± 42.0) mg/L, and there were statistical differences (F=21.08, 6.08 and 27.54;P<0.01). With the decreasing level of serum CHE, the serum levels of ALB and PA were all gradually decreased, ALB:(45.4 ± 10.1), (33.1 ± 4.2) and (31.5 ± 8.8) g/L;PA:(209.3 ± 56.4), (108.4 ± 44.1) and (81.5 ± 49.6) mg/L, and there were statistical differences (F = 70.23 and 152.57, P<0.01). The bivariate Spearman correlation analysis result showed that the serum HCV-RNA level was negatively correlated with serum CHE, ALB and PA (r =-0.357, -0.326 and-0.471; P<0.05), and the serum CHE was positively correlated with serum ALB and PA (r=0.726 and 0.807, P<0.05). Conclusions The serum HCV-RNA level is closely related to liver function indices. Performing simultaneous detection of serum HCV-RNA level and serum PA is helpful in the early diagnosis and treatment of Hepatitis C.

Objective To investigate the influence of high-voltage electrical burn on the throm-bomodulin (TM), protein C (PC), protein S (PS) and D-Dimer (D-D) in SD rats. Methods One hundred and twenty healthy SD rats were divided into the fake high-voltage electrical burn groups (FHEB), high-voltage electrical burn groups (HEB) according to the random number table, with 60 rats in each group. Ten rats were taken from each group at 15 minutes before injury. Plasma were collected from heart blood. Fifty SD rats of HEB group with voltage regulator and experimental transformer. The remaining fifty SD rats of FHEB group were sham injured with the same devices without electric current. At 5 minutes and 1, 2, 4, 8 hour (s) post injury, 10 rats of every group were randomly chosen at each time point for observation of the concentrations of TM, PC, PS and D-D. Plasma were collected from heart blood. Data were processed with analysis of variance of factorial design and LSD test. Results Compared with the FHEB group, the concentration of TM from 5 minutes to 8 hours post injury in HEB group was higher significantly (P < 0.05). Exception of the concentrations of PC and PS at 15 minutes before injury, the concentrations of PC and PS were lower than those of FHEB group (P < 0.05). The concentration of D-D in HEB group peaked at 8 hours post injury in (173.05 ± 4.08) ng/mL. Conclusion High-voltage electrical burn at early stage can increase the concentrations of TM, D-D, as well as decrease the concentrations of PC and PS, which are not only causing the vascular endothelium damage but also possessing serious effect on the thromboplastin function of SD rats.

BACKGROUNDCluster of differentiation 44 (CD44) is a family of transmembrane glycoproteins. As cell surface hyaluronate receptor, it has been found to be widely expressed in a variety of cells. The aim of this study is to assess the relationship among CD44 expression, DNA content, proliferation index (PI) and apoptosis in female adenocarcinoma of the lung.

METHODSThe expression of CD44, DNA index (DI), PI and apoptotic rate were studied in 61 cases of female adenocarcinoma of the lung, paracancerous tissues and 45 cases of benign lesions by flow cytometry.

RESULTSThe percent of DNA aneuploidy was 75.41% in adenocarcinoma. The expression of CD44, DI and PI in adenocarcinoma were significantly higher than those in paracancerous and benign controls (P < 0.01), however the apoptotic rate was obviously lower in adenocarcinoma than that in paracancerous and benign controls (P < 0.01). There was a positive correlation between CD44 and DI (P < 0.01), and a negative correlation between apoptosis and DI in adenocarcinoma (P < 0.01).

CONCLUSIONSThe expression of CD44, DNA content, proliferation and apoptosis may play important regulating roles in oncogenesis, development and metastasis of female adenocarcinoma of the lung.

BACKGROUNDXeroderma pigmentosum group D (XPD) is one of the important DNA repair genes. XPD polymorphism at Lys751Gln site has been shown to alter XPD protein function, modulate DNA repair capacity and therefore affect cancer risk. The aim of this study is to explore the relationship between XPD polymorphism and susceptibility to lung cancer in nonsmoking female via a population-based case-control study.

METHODSThere were 105 female patients who were diagnosed with lung cancer between January 2004 and December 2005 from Liaoning Tumor Hospital and 202 Hospital, and the control group included 105 healthy volunteers who were obtained from community centers at the same time. Information concerning demographic and risk factors was obtained for each case and control by a trained interviewer. XPD genotypes of cases and controls were determined by PCR-RFLP method. Two-sided Chi-Square test was used to compare the distribution of the genotypes and risk factors between cases and controls. Unconditional logistic regression analysis was performed to calculate the odds ratios (OR) with 95% confidence intervals (CI) for estimating the association between certain genotypes and lung cancer and exploring the interaction of environmental risk factors and genetic polymorphism.

RESULTSAll of the subjects in this study were nonsmoking females in Shenyang. There was no significant demographic difference (age, economic level and education) between cases and controls. There was a significant difference in the frequencies of XPD polymorphism between cancer cases and controls. The frequencies of XPD 751Gln allele were 6.2% in controls and 13.8% in cases (P < 0.05). The risk of lung cancer was higher in those with the Lys/Gln or Gln/Gln genotype than in those with the Lys/Lys genotype and adjusted OR was 2.80 (95% CI: 1.21-6.48). The result showed that cooking fumes exposure was a risk factor for lung cancer (OR was 2.44). Furthermore, an interaction between environmental risk factors and the variant XPD 751Gln allele on the risk of lung cancer was observed. Individuals with both risk gen-otype and exposure to cooking fumes had a higher elevated risk of cancer than those with only one of them (adjusted OR= 6.85 ; 95% CI: 1.69-27.67; P=0.007).

CONCLUSIONSThe above findings indicate that the Lys751Gln polymorphism in XPD gene is associated with the risk of lung cancer in nonsmoking females. Individuals with both XPD 751Gln allele genotype and exposure to cooking fumes have a higher elevated risk of cancer than those with only one of them in nonsmoking female population.

BACKGROUNDXRCC1 polymorphism at Arg399Gln site has been shown to modulate DNA repair capacity. The aim of this study is to assess the relationship between XRCC1 polymorphism and susceptibility to lung adenocarcinoma in nonsmoking female via a hospital-based case-control study.

METHODSCases were 126 female patients with lung adenocarcinoma from January 2002 to October 2004 in China Medical University Hospital and Liaoning Tumor Hospital. Controls were selected from patients with other pulmonary diseases in the hospitals at the same time. These controls were matched to cases on age (±5 years). Information concerning demographic and risk factors was obtained for each case and control by a trained interviewer. XRCC1 genotypes were determined by PCR-RFLP. The adjusted odds ratio (OR) and 95% confidence interval (CI) were calculated using logistic regression.

RESULTSCases showed a higher prevalence of oil smoke compared with controls (P < 0.05). The frequencies of Arg/Arg, Arg/Gln and Gln/Gln in lung adenocarcinoma group (32.54%, 42.86%, 24.60%) were significantly different from those in controls (54.76%, 40.48%, 4.76%) (P < 0.05). The individual carrying Gln/Gln genotype was at a significantly increased risk of lung adenocarcinoma compared with those with Arg/Arg genotype (OR=8.695, 95%CI 3.343-22.614, adjusted for age and oil smoke exposure). Furthermore, the OR of lung adenocarcinoma for the variant XRCC1 399Gln allele combined with exposure to oil smoke was 5.21 (95%CI 1.85-14.70, P < 0.001).

CONCLUSIONSThe results indicate that the Arg399Gln polymorphism in XRCC1 is associated with the risk of lung adenocarcinoma in nonsmoking women.