Immobilized enzyme-based enzyme electrode biosensors, characterized by high sensitivity and efficiency, strong specificity, and compact size, demonstrate broad application prospects in life science research, disease diagnosis and monitoring, etc. Immobilization of enzyme is a critical step in determining the performance (stability, sensitivity, and reproducibility) of the biosensors. Random immobilization (physical adsorption, covalent cross-linking, etc.) can easily bring about problems, such as decreased enzyme activity and relatively unstable immobilization. Whereas, directional immobilization utilizing amino acid residue mutation, affinity peptide fusion, or nucleotide-specific binding to restrict the orientation of the enzymes provides new possibilities to solve the problems caused by random immobilization. In this paper, the principles, advantages and disadvantages and the application progress of enzyme electrode biosensors of different directional immobilization strategies for enzyme molecular sensing elements by specific amino acids (lysine, histidine, cysteine, unnatural amino acid) with functional groups introduced based on site-specific mutation, affinity peptides (gold binding peptides, carbon binding peptides, carbohydrate binding domains) fused through genetic engineering, and specific binding between nucleotides and target enzymes (proteins) were reviewed, and the application fields, advantages and limitations of various immobilized enzyme interface characterization techniques were discussed, hoping to provide theoretical and technical guidance for the creation of high-performance enzyme sensing elements and the manufacture of enzyme electrode sensors.

AIM To establish the HPLC characteristic chromatograms for Yixin Fumai Granules,and to determine the contents of sodium danshensu,protocatechualdehyde,chlorogenic acid,calycosin-7-O-β-D-glucoside,ferulic acid,rosalinic acid,salvianolic acid A,salvianolic acid B,schisandrol A.METHODS The analysis was performed on a 35 ℃ thermostatic Acutfex PA-C18 column(4.6 mm ×250 mm,5 μm),with the mobile phase comprising of acetonitrile-0.1％phosphoric acid flowing at 1.0 mL/min in a gradient elution manner,and the detection wavelengths were set at 210,250,280,320 nm.Subsequently,cluster analysis and principal component analysis were performed.RESULTS There were 11 characteristic peaks in the characteristic chromatograms for 15 batches of samples with the similarities of more than 0.980.Nine constituents showed good linear relationships within their own ranges(r≥0.999 6),whose average recoveries were 97.60％-107.02％with the RSDs of 0.78％-1.87％.Various batches of samples were clustered into 4 categories,2 principal components demonstrated the accumulative variance contribution rate of 89.454％.CONCLUSION This sensitive and reproducible method can provide a reference for the quality evaluation and control of Yixin Fumai Granules.

Objective:To investigate the clinical characteristics of children with cervicothoracic hemivertebra at different ages and evaluate the surgical outcomes of hemivertebra resection.Methods:This retrospective cohort study analyzed clinical and radiographic data of 35 children (under 18 years old) with cervicothoracic hemivertebra who underwent one-stage posterior hemivertebra resection at the Department of Spine Surgery, Second Xiangya Hospital of Central South University, from June 2005 to June 2022. The cohort included 19 males and 16 females, with a surgical age of (9.7±4.1) years (range: 3 to <18 years). Patients were divided into three groups based on initial surgical age: preschool group (≤5 years, n=10), school-age group (6 to 10 years, n=10), and adolescent group (11 to <18 years, n=15). The intraoperative blood loss, operative time, number of fixed vertebrae, and perioperative and postoperative complications were recorded. Radiographic measurements were taken preoperatively, postoperatively, and at final follow-up, including the Cobb angle of the primary curve, curve length, distal curve Cobb angle, neck tilt, shoulder balance, coronal balance, trunk tilt, clavicle angle, head deviation, and local kyphosis. Statistical analyses included one-way ANOVA, Kruskal-Wallis H test, chi-square test, and Fisher′s exact test. Results:The operative time was (333±74) minutes (range:200 to 450 minutes), the intraoperative blood loss was (419±132) ml (range:200 to 650 ml), and the number of fixed vertebrae was (6.0±2.7) segments (range:2 to 12 segments). Preoperatively, the preschool group had a smaller primary curve Cobb angle compared to the adolescent group (33.6°±8.4° vs. 43.0°±9.4°, F=3.394, P=0.046) and distal curve Cobb angle (6.4°±2.4° vs.11.9°±4.5°, F=6.550, P=0.038). The preschool group had better coronal balance ((8.8±4.3) mm vs. (20.2±11.7)mm, F=9.448, P=0.009) and trunk tilt (4.0°±2.0° vs.7.0°±3.0°, F=4.343, P=0.029) than the school-age group. The preschool group had fewer fused vertebrae than the school-age and adolescent groups (3.8±1.6 vs. 7.0±2.6 vs. 6.8±2.6, F=10.480, P=0.005). The preschool group also had less intraoperative blood loss than the adolescent groups ((320±125) ml vs. (480±113) ml, F=8.666, P=0.013). However, no significant differences were found in postoperative and final follow-up measurements of primary and distal curve Cobb angles, neck tilt, shoulder balance, coronal balance, trunk tilt, clavicle angle, head deviation, local kyphosis, or complication rates (all P>0.05). Conclusions:Children with cervicothoracic hemivertebra across different age groups exhibit similar surgical outcomes and complication rates. But the preschool group had fewer fixed segments and less intraoperative blood loss, suggesting that this age group is an ideal time for surgery.

The incidence of non-alcoholic fatty liver disease(NAFLD)has been increasing annually.Current primary treatment strategies involve dietary modifications and increased physical activity to allevi-ate symptoms,yet there is a notable lack of targeted pharmacological interventions.Members of the micro RNA-29(miR-29)family(miR-29a,miR-29b,miR-29c)are known to play a critical regulatory role in lipid metabolism within hepatocytes;however,the underlying mechanisms remain to be elucidated.This study aims to identify the target genes and associated signaling pathways of the miR-29 family,thereby providing potential therapeutic targets for the development of NAFLD treatments.Firstly,the human liver cell line HepG2 was utilized as a model for adipogenic induction,and miR-29a/b/c-3p mimics were indi-vidually transfected.Through methods such as Oil Red O staining and triglyceride(TG)quantification,it was observed that the miR-29 family members significantly inhibited lipid accumulation in hepatocytes(P＜0.05).Subsequently,qRT-PCR and Western blot were utilized to detect the expression levels of ad-ipogenic marker genes(fatty acid synthase(FAS),acetyl coa carboxylase(ACACA),stearoyl-coen-zyme a desaturase 1(Scd 1))and autophagy marker genes(sequestosome 1(SQSTM1,also known as p62),autophagy related gene 5(Atg5)),and the results indicated that the members of the miR-29 fam-ily could significantly suppress the expression of FAS,ACACA,Scd1,and p62 genes in hepatocytes,while significantly enhancing the level of the Atg5 gene.Further investigations using signaling pathway activity analysis and dual luciferase reporter assays confirmed that the miR-29a/b/c could suppress the mTOR signaling pathway activity and directly interact with the ten-eleven translocation 2(TET2)gene.Finally,co-transfection experiments were performed to examine the potential synergistic effects among the miR-29-3p family members,and the results demonstrated that co-transfection of miR-29 family members more effectively inhibited lipid droplet accumulation in HepG2 cells and further suppressed the expression of the target gene TET2 compared to individual transfection.In summary,the miR-29 family members may reduce lipid accumulation in hepatocytes by inhibiting the mTOR signaling pathway via the TET2 gene,and they exhibit a positive synergistic effect.

Objective:To construct a machine learning classification prediction model using planning-omics (planomics) features to predict the γ pass rate of intensity-modulated radiotherapy (IMRT) plan dose verification in fixed-field thoracic tumors, and evaluate the application of planomics in radiotherapy quality assurance.Methods:The fixed-field IMRT plans of 240 patients with chest tumors admitted to Department of Radiotherapy, Henan Cancer Hospital from August 2022 to March 2023 were retrospectively analyzed. All plans underwent dose verification using the electronic portal imaging system detector on the Varian accelerator to collect field dose data. The dose verification results were analyzed through Portal Dosimetry in the treatment planning system of Eclipse. The γ pass rate standard was set at 2%/2 mm with a 10% dose threshold. From the planning documents, 48 conventional planning features, 2476 planomics features, and the combination of the previous two feature sets were extracted. Subsequently, an auto-encoder classification model was constructed. To evaluate the classification efficacy of various feature sets, 20 random train-test divisions were conducted by calculating the area under the receiver operating characteristic curve (AUC) values along with the accuracy rates.Results:After the feature selection, 2 conventional features and 16 planomics features were finally selected. In the testing set, the AUC values for the model using combined features, planomics features, and conventional planned features were 0.802±0.030, 0.740±0.069, and 0.673±0.083, respectively. In contrast, in the training set, these AUC values were 0.844±0.074, 0.816±0.047, and 0.687±0.036, respectively. The accuracy rates were 0.752±0.083, 0.703±0.110, and 0.648±0.081 in the testing set, and 0.753±0.098, 0.751±0.075, and 0.624±0.054 in the training set for the combined, planomics, and conventional planning feature sets, respectively.Conclusions:For thoracic fixed-field adjusted radiotherapy planning, the machine learning method based on planomics features can be utilized to build a classification model for predicting the γ pass rate. Combining planomics features with conventional planned features can enhance the predictive performance of the classification models.

Objective:To investigate the application value of dual-layer detector spectral CT in the precise outlining of gross tumor volume (GTV) in lung cancer patients.Methods:Imaging data of 39 patients with pathologically confirmed lung cancer on dual-energy enhanced CT scans in Hebei Medical University Third Hospital were retrospectively analyzed. Among them, 13 patients were not complicated with lung atelectasis and 26 cases were complicated with lung atelectasis and 9 of them received positron emission computed tomography (PET-CT) scan. The virtual single-energy images of arterial and venous dual-phase 40 keV images were reconstructed with the spectral base images of Iqon dual-energy CT, and the GTV of the primary foci was outlined using the reconstructed images and conventional enhanced CT images. The GTV outlined by conventional enhanced CT image, 40 keV virtual monoenergetic (VM) CT image, 40 keV VM-iodine density (VM-ID) fusion image in the arterial phase, conventional enhanced CT image, 40 keV VM image and 40 keV VM-ID image in the venous phase and PET-CT image was defined as GTV ACT, GTV A40VM, GTV A40VMID, GTV VCT, GTV V40VM, GTV V40VMID and GTV PET-CT, respectively. The consistency of target area outlining was assessed by calculating the GTV volume, the Dice similarity coefficient (DSC), and the 95 th percentile of the Hausdorff distance (HD95). Pairwise comparison among groups was conducted by Friedman test and corrected by Bonferroni correction. Results:In GTV comparisons, the differences in GTV ACT, GTV VCT, GTV A40VM and GTV V40VM in patients without pulmonary atelectasis were not statistically significant ( χ2=1.89, P=0.595). The DSC and HD95 of GTV ACTvs. GTV A40VM were 0.96 and 3.00, and the DSC and HD95 of GTV VCTvs. GTV V40VM were 0.94 and 2.93, respectively. The differences in GTV ACT, GTV A40VM, GTV A40VMID, GTV VCT, GTV V40VM, GTV V40VMID and GTV PET-CT in patients complicated with pulmonary atelectasis were statistically significant (all P<0.001). Pairwise comparison of Bonferroni correction showed that there was no statistically significant difference in GTV A40VM, GTV A40VMID, GTV V40VM, GTV V40VMID and GTV PET-CT (all P=1.000), all of which were significantly smaller than those of GTV ACT and GTV VCT (both P=0.001), and there was no statistically significant difference between GTV ACT and GTV VCT (both P=1.000). Based on the tumor extent shown by PET-CT (standardized uptake value =2.5), DSC were slightly higher and HD95 were slightly lower than conventional enhanced CT of GTV A40VM, GTV V40VM, GTV A40VMID, GTV V40VMIDvs. GTV PET-CT, respectively. When the arterial phase sequences were compared with PET-CT, pairwise comparison of Bonferroni correction showed that the DSC and HD95 of GTV A40VMvs. GTV PET-CT and GTV ACTvs. GTV PET-CT were statistically significant (both P<0.01), and the differences were not statistically significant among the remaining groups (all P>0.05). When intravenous phase sequences were compared with PET-CT, pairwise comparison of Bonferroni correction revealed that the DSC and HD95 of GTV V40VMIDvs. GTV PET-CT and GTV VCTvs. GTV PET-CT were statistically significant (both P<0.01), and the differences were not statistically significant among the remaining groups (all P>0.05). Conclusions:The use of 40 keV VMI-ID fusion images to outline the target area of the primary tumor lesions is closer to that of PET-CT, which provides a novel option for the precise outlining of the target area of clinical radiotherapy.

Objective:To evaluate the detection capability of the contrast-enhanced three-dimensional turbo spin-echo (CE-SPACE) sequence for brain metastases (BM), aiming to provide evidence for precise target delineation in stereotactic radiotherapy (SRT).Methods:A total of 123 BM patients who received radiotherapy at the Affiliated Cancer Hospital of Zhengzhou University from May to November 2024 were enrolled. All patients underwent contrast-enhanced (CE) MRI and CT scans in the same treatment position, with images rigidly registered in the Eclipse planning system. Two experienced radiation oncologists independently delineated BM lesions on CE-MPRAGE and CE-SPACE sequences in a blinded manner. Patients were divided into the delayed group (10 min, n=61) and a priority group (5 min, n=62) based on the time interval between gadolinium injection and CE-SPACE acquisition. The non-parametric Wilcoxon rank-sum test was used to compare the lesion counts and volume differences between the two imaging sequences. Point-biserial correlation analysis was performed to assess the correlation between the additional lesions identified by CE-SPACE and lesion volume. Results:The overall analysis demonstrated that CE-SPACE detected 421 BM lesions, achieving an 8.2% higher detection rate than CE-MPRAGE ( Z=3.78, P<0.001). In terms of lesion volume, the median BM lesions volume identified by CE-SPACE [0.30(0.07,1.53)cm 3] was 8.7% larger than that by CE-MPRAGE [0.23 (0.04, 1.34) cm 3] ( Z=12.88, P<0.001). CE-SPACE demonstrated superior sensitivity for lesions ≤ 0.06 cm3, with negative correlation between the number of additional lesions detected and lesion volume ( r=-0.104, P=0.034). Subgroup analysis revealed that in the delayed group, CE-SPACE detected significantly more lesions [median 2 (1, 3.5) vs. 2 (1, 3), P=0.002] and larger volumes [0.39 (0.08, 2.24) cm3 vs. 0.29 (0.05, 1.99) cm3, P<0.001] than CE-MPRAGE. In the priority group, CE-SPACE detected significantly larger lesion volumes [0.55 (0.09, 2.06) cm3 vs. 0.45 (0.08, 1.88) cm3, P<0.001], but no significant difference was observed in lesion counts between two sequences ( P=0.059). Conclusions:Three-dimensional CE-SPACE sequence offers superior detection sensitivity for small BM (≤ 0.06 cm3), providing crucial guidance for accurate target delineation in SRT.

Objective To analyze the global literature related to functional cure of hepatitis B from 2019 to 2023 by using bibliometric analysis methods,so as to help researchers understand the research hotspots and trends in this field.Methods The literature related to the topic of functional cure of hepatitis B included in the Science Citation Index Expanded(SCI-Expanded)of the Web of Science Core Collection from 2019 to 2023 was searched.By using VOSviewer and CiteSpace visual analysis tools,analyses were conducted from the perspectives of publication trends,international research cooperation networks,and keyword emergence,and were elaborated with the specific contents of the related literature to elucidate research hotspots and trends.Results A total of 600 eligible papers in this field were included.Keyword co-occurrence and thematic clustering suggested that the main research directions of functional cure were:serum biomarkers for prediction and monitoring of functional cure,functional cure and immunity,nucleoside analog discontinuation,interferon therapy,and long-term prognosis of functional cure.The research contents of the ESI highly cited original research papers were similar to the clustering of the above,but showed more attention on the novel agents for functional cure.The content of the keyword emergence map showed that hotspots of interest changed from virologic mechanisms and serum markers,to nucleoside analog discontinuation and interferon therapy,and finally to immunologic mechanisms and new drug.Conclusion The research hotspots and trends of functional cure of hepatitis B were focused on virological mechanism,serum markers,immunological mechanism,nucleoside analog discontinuation,interferon therapy,and long-term prognosis after cure.

Objective To explore the predictive efficacy of several multimodal MRI-based machine learning models for the promoter methylation states of O6-methylguanine-DNA methyltransferase(MGMT)of glioblastoma muliforme(GBM)patients in terms of the GBM heterogeneity and the complexity of the tumor microenvironment.Methods Firstly,the multimodal MRI images of 317 GBM patients from The University of Pennsylvania Glioblastoma(UPENN-GBM)dataset were pre-processed,with four sequences involved in including T1-weighted imaging(T1WI)sequence,T1-weighted contrast-enhanced imaging(T1CE)sequence,T2-weighted imaging(T2WI)sequence and fluid-attenuated inversion recovery(FLAIR)sequence,and the radiomics features were extracted for two regions of interest(ROIs)such as the tumor core region and the tumor edema region.Secondly,the data of the 317 GBM patients were randomly divided into a training set(254 cases)and a test set(63 cases),which underwent normalization with Z-scores and feature selection and dimensionality reduction with Lasso regression.Finally,three models were established respectively with particle swarm optimization-support vector machine(PSO-SVM),C-support vector classification(C-SVC)and adaptive boosting(adaptive boosting(Adaboost)algorithms,and the predictive efficacy of the three models for glioblastoma multiforme MGMT promoter methylation states were evaluated in terms of accuracy and AUC.Results The Adaboost model based on T2WI sequence and radiomics features of the tumor core region had the highest predictive efficacy with accuracy and AUC values of 67％and 0.74,respectively,higher than those of other combinations of sequences,models and regions of interest.Conclusion The multimodal MRI-based machine learning models can be used for the prediction of glioblastoma multiforme MGMT promoter methylation states,which provides powerful support for personalized treatment and prognostic assessment of GBM.[Chinese Medical Equipment Journal,2025,46(6):7-13]

In view of the characteristics of H5N6 subtype avian influenza virus(AIV)that it has both high pathogenicity and the risk of cross-species transmission,posing a serious threat to the poultry farming industry and public health security,in order to effectively prevent and control the spread of H5N6 avian influenza,a rapid,sensitive and specific detection technolo-gy was established in this study.The specific monoclonal antibodies against the neuraminidase N6 protein of avian influenza A virus subtype H5N6 were obtained through hybridoma and monoclonal antibody technology.These antibodies were coupled and labeled with carboxyl-functionalized fluorescent quantum dots,along with previously prepared specific antibodies against the hemagglutinin H5 protein.A rapid fluorescence immunochromatographic detection method for the H5N6 subtype of avian influ-enza virus was established according to the principle of double-antibody sandwich immunochromatography.This method a-chieved a detection sensitivity of 1 ng/mL for recombinant hemagglutinin H5 subtype protein and 0.1 ng/mL for recombinant neuraminidase N6 subtype protein.Moreover,the method exhibited no cross-reactivity with other influenza subtypes or patho-gens,such as Newcastle disease(ND),infectious bronchitis(IB),and infectious laryngotracheitis(ILT),thus demonstrating good specificity.The method effectively identified the highly pathogenic avian influenza virus H5 subtype and directly distin-guished the H5N6 subtype with good accuracy.The fluorescent quantum dot immunochromatographic typing detection method established herein met the sensitivity,specificity,and accuracy requirements for H5N6 subtype detection,and can be further used for rapid detection of the H5 and H5N6 subtypes of avian influenza virus.