The principe of electrical impedance tomography(EIT)was described,and the research progress of EIT technology in the field of gesture recognition was reviewed from the aspects of hardware system and gesture recognition algorithm.The challenges of EIT technology applied in the field of gesture recognition were analyzed,and the future development trends were envisioned.[Chinese Medical Equipment Journal,2025,46(4):93-99]

Objective:To prepare nanoscale docetaxel-loaded lipid microbubbles(DLLM),characterize their physical and chemical properties,evaluate their biosafety and anti-tumor effects in vitro,and explore their potential as a targeted delivery system for chemotherapeutic drugs.Methods:DLLM was prepared by thin film hydration method.The morphology,particle size and distribution were characterized by transmission electron microscopy,scanning electron microscopy and particle size analyzer.The drug encapsulation efficiency was determined by high performance liquid chromatography.Human hepatoma HepG2 cells were used as a model to set up the control group(Control group),the docetaxel group(DOC group),the docetaxel-loaded lipid microbubbles group(DLLM group)and the docetaxel-loaded lipid microbubbles+ultrasound group(DLLM+US group).The cell morphology was observed by optical microscope,the cell survival rate was detected by CCK-8 method,and the apoptosis was detected by flow cytometry.The biocompatibility of microbubbles and their mediated ultrasound-enhanced anti-tumor effect were evaluated.Results:The prepared DLLM was regular spherical,with a particle size distribution range of 200-600 nm,an average particle size of 380 nm,and an encapsulation efficiency of 80.3％±2.6％.The cell viability of the DOC group and the DLLM+US group was significantly lower than that of the Control group(P＜0.01),and the apoptosis rate was significantly increased(P＜0.01).The cell viability of the DLLM+US group was lower than that of the DOC group(P＜0.05),and the apoptosis rate was higher than that of the DOC group(P＜0.05).There was no significant difference in cell viability and apoptosis rate between the DLLM group and the Control group(P＞0.05).Conclusions:The nano-scale DLLM prepared in this experiment has uniform particle size,high encapsulation efficiency,good stability and biocompatibility.DLLM can enhance the killing and pro-apoptotic effects of docetaxel on HepG2 cells under ultrasound irradiation.

Objective To determine the knee joint cartilage thickness using different methods and explore the feasibility of mathematical statistical models of dataset for the prediction of cartilage thickness.Methods A total of 304 patients diagnosed as knee osteoarthritis(OA)combined with varus deformity and undergoing unilateral total knee arthroplasty at the Second Affiliated Hospital of Army Medical University from March 2023 to March 2024 were selected for the study.All patients had complete preoperative and postoperative clinical data.The healthy cartilage at four anatomical sites of patients,including the distal femur lateral condyle,lateral tibial plateau,posterior medial femoral condyle,and posterior lateral femoral condyle were selected,and the knee joint cartilage thickness was determined based on preoperative MRI analysis,robotic navigation system tracing,tissue section of surgical specimen and digital vernier caliper.The baseline indicators of demographics,disease and imaging ffor patients were collected to construct a dataset,and four models of linear regression analysis,principal component analysis,Least Absolute Shrinkage and Selection Operator(LASSO)regression analysis,and K-nearest neighbors(KNN)analysis were established for predicting the accuracy,determination coefficient(R2)and root mean square error(RMSE),and the regression equation for predicting cartilage thickness was established.Results The knee joint cartilage thicknesses determined by preoperative MRI analysis,robotic navigation system tracing,tissue section of surgical specimen had no statistically significant difference with that by digital vernier caliper(P>0.05).The predictive efficiencies of models of linear regression analysis,principal component analysis,and LASSO regression analysis for the knee joint cartilage thickness all failed to meet the expectations(R2<0.3,RMSE>0.03).The predictive effect of KNN model on the cartilage thickness of the distal femur lateral condyle and lateral tibial plateau was not ideal(R2=0.23,RMSE=0.29),while it had potential predictive value(accuracy=0.21,accuracy=0.15).Conclusion The prediction model of knee joint cartilage thickness based on individual parameters has certain scientificity,and the feasibility of KNN model is relatively high.However,due to insufficient sample size and unclear individual parameter weight,the efficiencies of the four established prediction models are not ideal,which fails to provide definite prediction equations.Therefore,the construction scheme of the prediction model still needs to be further optimized.

Objective:To explore the safety and efficacy of intraosseous regional administration (IORA) of vancomycin for preventing infection in primary total knee arthroplasty (TKA).Methods:A total of 124 patients with knee osteoarthritis undergoing TKA between February 2024 and May 2024 at nine hospitals were enrolled. Preoperative infection prophylaxis involved either IORA (0.5 g vancomycin administered via intraosseous regional infusion before incision) or intravenous infusion (1 g vancomycin via peripheral vein). The IORA group included 15 males and 47 females with a median age of 66.5 years (range, 60.0-70.0 years), while the intravenous group included 14 males and 48 females with a median age of 66.0 years (range, 61.8-70.3 years) years. Intraoperative samples were collected including fat and synovium tissues after incision, before prosthesis placement, and after tourniquet release; distal femoral cancellous bone during femoral osteotomy; proximal tibial cancellous bone during tibial osteotomy; proximal intercondylar cancellous bone before prosthesis placement; and peripheral blood from non-infused arms at surgery initiation and after tourniquet release. Vancomycin concentrations were measured using liquid chromatography-tandem mass spectrometry. Vital sign changes were recorded from admission to 5~10 minutes post-IORA (IORA group) or post-incision (intravenous group). Follow-ups were conducted on postoperative day 1 and 3, and at 1 and 3 months, to document complications including IORA-related adverse events, periprosthetic joint infections, surgical site infections, red man syndrome, acute kidney injury, deep vein thrombosis and so on.Results:Vancomycin concentrations in bone, fat, and synovial tissue samples were significantly higher in the IORA group than in the intravenous group ( P<0.05), while vancomycin concentrations in blood samples were significantly lower in the IORA group than in the intravenous group ( P<0.05). Only 7.3%(41/558) of tissue samples in the IORA group had vancomycin concentrations below 2.0 μg/g (the minimum inhibitory concentration of vancomycin against coagulase-negative staphylococcus), compared to 59.3%(331/558) in the intravenous group (χ 2=11.285, P<0.001). In the intravenous group, 16.9%(21/124) of blood samples had vancomycin concentrations exceeding 15.0 mg/L (the threshold associated with a significantly increased risk of nephrotoxicity), while all concentrations in the IORA group were below this threshold, the difference was statistically significant (χ 2=22.943, P<0.001). There were no statistically significant difference ( P>0.05) in vital signs changes before and after vancomycin administration between the two groups. Two patients in the intravenous group experienced incision exudate, while no other related complications occurred in either group. Conclusions:Compared to the traditional intravenous infusion of 1 g vancomycin, intraosseous injection of a low dose (0.5 g) of vancomycin achieves higher local tissue concentrations in the knee joint with a lower incidence of adverse reactions and is safe for infection prophylaxis. Despite guidelines not recommending the routine use of vancomycin for preventing infection after primary TKA, intraosseous injection of 0.5 g vancomycin may be considered intraoperatively for primary TKA in the following scenarios: patients in medical institutions with a high prevalence of methicillin-resistant staphylococcus aureus (MRSA) infections, patients with potential preoperative MRSA colonization, or patients with cephalosporin allergy.

Objective To investigate the expression characteristics and clinical diagnostic value of programmed death receptor 1(PD-1)and its corresponding ligand(PD-L1)in patients with acute exacerbation of chronic obstructive pulmonary disease(AECOPD).Methods One hundred and sixty COPD patients who visited Dongzhimen Hospital of Beijing University of Chinese Medicine from April 2024 to November 2024 were included and divided into an acute exacerbation group of 100 cases and a stable group of 60 cases according to the severity of the disease.Additionally,40 healthy volunteers during the same period were recruited as the control group.The general clinical data of the patients were collected.Chronic Obstructive Pulmonary Disease Assessment Test(CAT)and Modified Medical Research Council Dyspnea Questionnaire(mMRC)Scale were used to test the severity of the disease;respiratory function testing was performed and fasting venous blood was collected for serum PD-1 and PD-L1 testing.Pearson correlation was used to analyze the correlation between serum PD-1,PD-L1,CAT,and mMRC,and multiple logistic regression analysis to identify the influencing factors of AECOPD.Receiver operating characteristic(ROC)curve was drawn to evaluate the diagnostic value of serum PD-1 and PD-L1 level for AECOPD.Results Serum PD-1 level in the stable COPD group and AECOPD group was significantly increased compared with that in the control group,while serum PD-L1 level was significantly decreased,showing statistical significance(P<0.05);The level of PD-1 gradually increased with the grading of lung function and the deterioration of AECOPD,with statistical significance(P<0.05);Pearson correlation showed that serum PD-1 level was positively correlated with CAT scores in COPD patients,while negatively with CAT scores,showing statistical significance(P<0.05);Multiple logistic regression analysis showed that elevated levels of serum inter-leukin-6(IL-6),neutrophil to lymphocyte ratio(NLR),and PD-1 were risk factors for AECOPD,while elevated level of PD-L1 was protective factor for AECOPD(P<0.05);ROC curve showed that the levels of PD-1,PD-L1,IL-6,NLR,and the area under the ROC curve(AUC)for their combined prediction of AECOPD diagnosis were 0.884,0.867,0.868,0.802,and 0.995,respectively.Conclusion Serum PD-1 and PD-L1 in AECOPD patients have presented certain expression characteristics,with elevated PD-1 level while decreased PD-L1 level.Both have good clinical diagnostic value for AECOPD.

Objective:To explore the structural relationship between WMSDs in the upper limbs and various risk factors in the occupational population in China, based on a large sample epidemiological survey and structural equation analysis, and to establish a structural equation model, so as to lay a foundation for the prevention and control of such diseases.Methods:The Chinese version of the Musculoskeletal Disorders Electronic Questionnaire was used to conduct a nationwide survey on the prevalence of WMSDs in the upper extremity. Six factors related to WMSDs in the upper extremity were extracted by the classification standard of adverse ergonomic factors and their source and confirmatory factor analysis, including work organization, work type, upper extremity work posture, individual factors, upper extremity fatigue and upper extremity WMSDs. The structural equation analysis was carried out and the structural equation model was established.Results:The incidence of WMSDs and fatigue in the upper limbs was 24.44% and 43.76%, respectively. The adjusted structural equation model fitting indicators were generally up to the standard (GFI=1.000, AGFI=1.000, RMSEA=0.043, NFI=0.808, TLI=0.784) . The four exogenous latent variables of work organization, work type, upper limb work posture and individual factors were correlated. There was a strong positive correlation between job type and upper limb work posture ( r=0.865) , a moderate positive correlation between work organization and job type and upper limb work posture ( r=0.570, 0.490) , and a weak negative correlation between individual factors and the other three exogenous latent variables. Upper limb work posture and individual factors had direct effects on upper limb WMSDs, and the effect coefficients were 0.10 and 0.06, respectively. Upper limb fatigue played a mediating role between work organization, work type, upper limb work posture and upper limb WMSDs. The effect coefficient was 0.46, and the composition ratios of indirect effects were 100.0%, 100.0%, and 38.3%, respectively. The direct path effect of upper limb work posture, individual factors and upper limb WMSDs was weaker than the mediating path through upper limb fatigue. Conclusion:When carrying out the prevention and control of upper limbWMSDs, it is necessary to comprehensively consider the pathogenesis path of upper limb muscle fatigue and upper limb WMSDs caused by work organization, work type, and upper limb work posture, so as to provide theoretical reference for improving the prevention and control level of such diseases.

Objective To analyze the correlation between lesion volume,lesion mass,and maximum lesion diameter in the assessment of advanced hepatocarcinoma with lung metastasis,and to evaluate the application value of total volume response and total mass response of lung metastatic lesions in efficacy assessment.Methods A retrospective analysis was conducted on the CT imaging data of 20 patients clinically confirmed with hepatocarcinoma and lung metastases,followed by subsequent follow-up to monitor their survival outcomes.Volume measurement software was used to measure the volume of lesions before and after treatment.We recored lesion diameter,volume measurements and CT values,calculated the mass of the lesions.The correlation between lesion volume,mass and diameter was analyzed,as well as the correlation between the change rates of volume,mass and lesion diameter.Additionally,the total volume and total mass of all lesions were calculated.The correlation between the change rates of total volume/total mass and the change rate of pulmonary lesion diameter under the RECIST 1.1 criteria,as well as the correlation with changes in patients'tumor markers,were analyzed.Furthermore,the overall volume response and overall mass response of lesions were evaluated based on changes in total volume and total mass,and their consistencies with the RECIST 1.1 criteria for efficacy evaluation were analyzed.Finally,univariate Cox regression analysis was performed to explore the association between these variables and patient survival outcomes.Results There was strong correlation between lesion volume,mass and tumor diameter(r=0.771,0.775),between the rate of change in mass and the rate of change in lesion diameter(r=0.846),and between the rates of change in total volume/total mass and the rate of change in pulmonary lesion diameter under the RECIST 1.1 criteria(r=0.800,0.896).The correlation between the rates of change in total volume/total mass and patients'tumor markers was not statistically significant.There was moderate correlation between the rate of change in volume and the rate of change in lesion diameter(r=0.692).The evaluation results of total volume response and total mass response for pulmonary lesions in advanced hepatocarcinoma with lung metastasis were generally consistent with the RECIST 1.1 criteria(Kappa=0.486,0.426).Univariate Cox regression analysis revealed that total lesion volume(P=0.047)and total lesion mass(P=0.049)were independent prognostic factors for survival outcomes.Conclusion Lesion volume,mass,and diameter,as well as their respective change rates,were found to be interrelated.Furthermore,total lesion volume and total lesion mass were identified as independent prognostic factors for survival outcomes.The total volume response and total mass response are promising evaluation methods in evaluating the efficacy of lung metastasis of hepatocarcinoma,which are different from the RECIST 1.1 evaluation criteria.

To investigate the antimicrobial resistance of Enterococci isolated from 596 anal swabs,feces and environmental samples were collected from pig,cattle,chicken and quail farms in Chang-sha,Hunan Province,Enterococci were isolated and identified by mass spectrometry.The minimum inhibitory concentrations(MICs)of 10 antimicrobial agents were determined by AGAR diffusion method.Whole genome sequencing(WGS)was used to detect the distribution of multilocus se-quence typing(ST),drug resistance genes and virulence genes.A total of 272 strains of Enterococ-cus were isolated(45.6％).The isolates were resistant to cefoxitin(68.9％)and cefotiofur(58.5％),followed by trimethoprim/sulfamethoxazole(52.2％),vancomycin(4.4％),and linezolid(13.6％).In this study,six linezolid highly resistant Enterococci isolates were analyzed by whole genome sequencing to explore the transmission mechanism of linezolid resistance because linezolid is forbidden to be used in aquaculture.ST403(4/6),ST16(1/6)and ST476(1/6)were the most common ST types,which all originated from the same farm.Three oxazolidinone resistance genes(cfr,poxtA and optrA)were found in all 21 strains.One strain(Ecc60)carried all three oxazo-lidinone resistance genes,but none of them were located on the plasmid.tet(M),aph(3')-Ⅲ,and lsa(A)were found in all six Enterococcus isolates.Interestingly,the present study is the first to i-dentify enterococci carrying the optrA gene in quail fecal samples.The analysis of the genetic envi-ronment of oxazolidinone resistance genes showed that the genetic environment of cfr(D),poxtA and optrA of isolates from the same farm was similar.A total of 19 virulence genes were detected in 6 isolates,of which 12 genes(ElrA,SrtA,ace,agg,cCF10,cOB1,cad,camE,ebpA,ebpC,efaAfs,tpx)were carried by all 6 isolates,and the types of virulence genes in strains from the same farm were extremely similar.The results showed that the drug resistance of Enterococci iso-lated from the fish farms in Changsha was serious,and the resistance rate to linezolid,which was prohibited in the fish farms,was high.The oxazolidinone resistance gene loci were accompanied by other resistance genes,especially the florfenicol resistance gene(FexA),which may be related to the abuse of florfenicol in the fish farms.

Aim To investigate the role of triggering receptor expressed on myeloidcells 2(TREM2)in syn-aptic plasticity induced by cocaine addiction.Methods C57BL/6J mice and Trem2 knockout mice were uti-lized in this study to evaluate the alterations in postsyn-aptic density protein 95(PSD-95)and synapsin 1(SYN1)within the cortex and hippocampus of co-caine-addicted mice by using immunological tech-niques.Results HE staining and Nissl staining showed increased neuronal damage in the hippocampus and cortex of mice after cocaine addiction.The results of immunohistochemistry and fluorescence of PSD-95 and SYN1 were consistent with the expression trend of Western blot.In the wild type mouse model,the ex-pression level of PSD-95 in the hippocampus and cortex was lower than that in the saline group,and the ex-pression of SYN1 was higher than that in the saline group.In the knockout mouse model,the expression levels of PSD-95 and SYN1 in the hippocampus and cortex were significantly higher than those in the saline group after cocaine addiction.The expression levels of PSD-95 and SYN1 in the hippocampus and cortex of cocaine knockout mice were higher than those of co-caine wild type mice.Conclusion Cocaine addiction can change the synaptic plasticity,and TREM2 plays a regulatory role in the synaptic plasticity of hippocampus and cortex in mice with cocaine injury.TREM2 is ex-pected to be a new target for studying the mechanism of cocaine addiction.

Objective To investigate the clinical features of patients with China Liver Cancer Staging(CNLC)stage Ⅲhepatocellular carcinoma(HCC)achieving five-year sustained complete remission(CR)after local treatment combined with systemic therapy,as well as potential contributing factors,and to provide a reference for optimizing the treatment of advanced HCC.Methods A retrospective analysis was performed for the clinical data of six patients with CNLC stage Ⅲ HCC who were treated in Department of Interventional Radiology,The First Affiliated Hospital of Soochow University,from January 2016 to December 2019 and achieved five-year sustained CR.Baseline characteristics,treatment modalities,and follow-up data were summarized,and a literature review was performed.Results The six patients had a mean age of 58.3±10.1 years,among whom five had stage Ⅲa HCC and one had stage Ⅲb HCC,and all patients had a history of hepatitis.The mean preoperative MELD score was 8.2±0.8 for the six patients,and there were five patients with Child-Pugh class A liver function and one with Child-Pugh class B liver function.All patients underwent transcatheter arterial chemoembolization,followed by sequential targeted drug therapy after surgery,with sorafenib for four patients and lenvatinib for two patients.Four patients with main portal vein tumor thrombus also received 125I seed implantation,one patient with the single-nodule type underwent radiofrequency ablation,and three patients received immunotherapy with camrelizumab.The median time to AFP normalization was 6 months,the median time from treatment to CR was 5.5 months,and the median follow-up time was 63 months.Conclusion Good liver function at baseline,an early and rapid reduction in AFP,and the combination of local treatment and systemic therapy are key factors for achieving long-term CR in patients with advanced HCC.Multi-center large-scale studies are needed in the future to further explore prognostic factors and optimize treatment regimens.