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.

Objective:To investigate the correlation factors of complete clinical response in idiopathic inflammatory myopathies(IIMs)patients receiving conventional treatment.Methods:Patients diagnosed with IIMs hospitalized in Peking University People's Hospital from January 2000 to June 2023 were in-cluded.The correlation factors of complete clinical response to conventional treatment were identified by analyzing the clinical characteristics,laboratory features,peripheral blood lymphocytes,immunological indicators,and therapeutic drugs.Results:Among the 635 patients included,518 patients finished the follow-up,with an average time of 36.8 months.The total complete clinical response rate of IIMs was 50.0％(259/518).The complete clinical response rate of dermatomyositis(DM),anti-synthetase syn-drome(ASS)and immune-mediated necrotizing myopathy(IMNM)were 53.5％,48.9％and 39.0％,respectively.Fever(P=0.002)and rapid progressive interstitial lung disease(RP-ILD)(P=0.014)were observed much more frequently in non-complete clinical response group than in complete clinical re-sponse group.The aspartate transaminase(AST),lactate dehydrogenase(LDH),D-dimer,erythrocyte sedimentation rate(ESR),C-reaction protein(CRP)and serum ferritin were significantly higher in non-complete clinical response group as compared with complete clinical response group.As for the treat-ment,the percentage of glucocorticoid received and intravenous immunoglobin(IVIG)were significantly higher in non-complete clinical response group than in complete clinical response group.Risk factor analysis showed that IMNM subtype(P=0.007),interstitial lung disease(ILD)(P=0.001),eleva-ted AST(P=0.012),elevated serum ferritin(P=0.016)and decreased count of CD4+T cells in peripheral blood(P=0.004)might be the risk factors for IIMs non-complete clinical response.Conclu-sion:The total complete clinical response rate of IIMs is low,especially for IMNM subtype.More effec-tive intervention should be administered to patients with ILD,elevated AST,elevated serum ferritin or decreased count of CD4+T cells at disease onset.

Objective:To evaluate the clinical value of a capillary electrophoresis-based method for gene diagnosis of hyperphenylalaninemia.Methods:In this single-center prospective study, 40 newborns with suspected hyperphenylalaninemia detected by neonatal liquid chromatography-tandem mass spectrometry screening at Nanjing Maternity and Child Health Care Hospital from February 2021 to February 2023 were included, with 22 males, 18 females and a mean age at diagnosis of 21.93 days.Capillary electrophoresis was used to detect 85 variants of the phenylalanine hydroxylase ( PAH) gene in 40 newborns with suspected hyperphenylalaninemia.The PAH gene of undiagnosed patients was further analyzed by Sanger sequencing.The detection rate, sensitivity and specificity of capillary electrophoresis were calculated. Results:Among these 40 newborns with suspected hyperphenylalaninemia, 71 PAH variants were detected by capillary electrophoresis, 32 patients were clearly diagnosed, only 1 pathogenic variant was found in 5 patients, and no pathogenic variant was found in the last 3 patients.Therefore, the detection rate, sensitivity and specificity of capillary electrophoresis for analysis of the PAH gene were 80.00%, 88.75% and 100%, respectively. Conclusions:The capillary electrophoresis-based method can rapidly, efficiently and accurately detect PAH gene variants at lower cost and is a promising gene detection method for hyperphenylalaninemia in clinical practice.

Objective:To investigate electrocardiogram (ECG) characteristics and related factors of gestational diabetes mellitus (GDM) complicated by depressive disorder.Methods:The clinical data of 243 patients with GDM who received treatment at Peking University Third Hospital from September 2021 to December 2022 were retrospectively analyzed. According to the scoring results of the Self-rating Depression Scale (SDS), these patients were divided into an observation group (GDM + depressive disorder, n = 51) and a control group (GDM alone, n = 192). The χ2 test was used to analyze the relationship between GDM complicated by depressive disorder and ECG diagnosis results. Additionally, the t-test was used to compare ECG indicators between the two groups. Results:Compared with the control group, patients in the observation group had a higher incidence of abnormal ECG indicators, including bradycardia ( χ2 = 4.68, P = 0.030), premature contraction ( χ2 = 10.78, P = 0.001), and atrioventricular block ( χ2 = 15.04, P < 0.001). However, there were no significant differences in the incidences of tachycardia, bundle branch block, or ST-T changes between the two groups (all P > 0.05). Compared with the control group, the observation group exhibited significantly increased heart rate [(73.43 ± 8.24) beats/min vs. (67.22 ± 5.08) beats/min], maximum QT interval [(419.09 ± 36.00) ms vs. (351.95 ± 32.07) ms], minimum QT interval [(363.31 ± 30.78) ms vs. (316.52 ± 29.10) ms], and QT dispersion [(55.78 ± 17.87) ms vs. (35.42 ± 13.18) ms, t = -5.13, -12.95, -10.08, -7.60, all P < 0.001]. Conclusion:Among patients with gestational diabetes mellitus, those with depressive disorder have an increased risk of exhibiting abnormal electrocardiogram patterns compared with those without depressive disorder.

Objective To investigate the therapeutic effect and mechanism of Jianwei Xiaozhang Tablets on rats with precancerous lesions of gastric cancer(PLGC).Methods Forty male SD rats were randomly divided into the normal group,the model group,the folic acid group and the Jianwei Xiaozhang Tablets group,with 10 rats in each group.In addition to the normal group,the other three groups of rats were prepared by gavage with Ranitidine Aqueous Solution combined with N-methyl-N'-nitro-N-nitrosoguanidine(MNNG)solution drinking method for the preparation of PLGC model.After successful modeling,drugs were administered accordingly for 7 weeks.The changes in body mass of rats during modeling and drug administration were recorded,the gross view of the stomach was observed and scored pathologically,the coefficients of spleen and liver were determined,the pathological changes in gastric tissue were observed by hematoxylin-eosin(HE)staining,enzyme-linked immunosorbent assay(ELISA)was used to measure serum gastrin(GAS),motilin(MTL)and glucagon(GC),Alisin Blue-Periodic Acid Schiff's(AB-PAS)staining was used to observe the thickness of the mucosal layer of gastric tissues,the expressions of phosphatidylinositol 3-kinase(PI3K),phosphorylated PI3K(p-PI3K),protein kinase B(Akt),phosphorylated Akt(p-Akt),and endothelial-type nitric oxide synthase(eNOS)proteins in gastric tissues were detected by protein immunoblotting(Western Blot),and the expression of vascular endothelial growth factor A(VEGFA)protein in gastric tissues was detected by immunofluorescence staining.Results Compared with the normal group,the body mass of rats in the model group grew slowly during the experimental period,gastric macroscopic pathological scores were significantly increased(P＜0.01),splenic coefficient and hepatic coefficient were significantly decreased(P＜0.01),the gastric tissues showed cuprocyte hyperplasia and intestinal chemotaxis,gastric tissues'inflammation scores were significantly increased(P＜0.01),the serum GAS content was significantly increased(P＜0.01),and the MTL,GC contents were significantly reduced(P＜0.05),and the thickness of the mucous membrane layer of gastric tissue was significantly reduced(P＜0.05),the protein expression levels of PI3K,p-PI3K,Akt,p-Akt and eNOS were reduced(P＜0.01),and the protein expression level of VEGFA was reduced(P＜0.01);compared with the model group,the above indexes of the Jianwei Xiaozhang Tablets group and the folic acid group were all significantly improved(P＜0.05 or P＜0.01),among which,the Jianwei Xiaozhang Tablets group had a better improvement effect in the proliferation of cup cells and intestinal chemotaxis in gastric tissues,the content of serum GAS,and the thickness of the mucous layer in gastric tissues.Conclusion The mechanism of the improvement of PLGC in rats by Jianwei Xiaozhang Tablets may be related to the activation of the PI3K-Akt-eNOS pathway,which in turn promotes the angiogenesis and repair of gastric damaged tissues.

Surface-enhanced Raman scattering(SERS)can detect molecules adsorbed on the surface of noble metals in monolayers and sub-monolayers,and provide structural information of molecules with high sensitivity,high accuracy,and fingerprint recognition and non-destructive detection.The SERS technology has been widely used in single-molecule detection,chemical reaction and engineering,biomedicine,nanomaterials and environmental detection,and so on.The spectral sensitivity and signal reproducibility of SERS are closely related to the type of noble metal substrate.In this paper,based on the mechanism of electromagnetic field enhancement(EM)and chemical enhancement(CM)of SERS,the affecting factors of SERS enhancement were analyzed,including the micro-nanostructure of SERS substrate,particle size,particle spacing,etc,the research and application of SERS substrate in recent years were summarized and reviewed,and the development direction of metal substrate,data analysis and application direction of SERS technology in the future were prospected.

An electrochemical chemical oxygen demand(COD)sensor was proposed based on a FTO/TiO2/PbO2 electrode and a thin-layer electrochemical cell.The FTO/TiO2/PbO2 electrode was characterized by X-ray photoelectronic spectroscopy(XPS),X-ray diffraction(XRD)spectroscopy and electrochemical technique,and the results indicated that the rapid decrease in the output signals of the electrochemical COD sensor could be attributed to oxidation of PbSO4 occurring on the surface of FTO/TiO2/PbO2 electrode.The PbO2 deposition time and concentration of Na2SO4 were further optimized and then the electrochemical COD sensor was challenged by real samples including laker water sample,river water sample and wastewater sample.The evolution trend of signals of the electrochemical COD sensor in response to lake and river water samples was identical with that obtained with the standard method(HJ/T399-2007,Water quality-determination of the chemical oxygen demand-fast digestion-spectrophotometric method).The electrochemical COD sensor exhibited significant increase in the signal intensity after the samples were switched from lake water to wastewater sample,and a mean value of 32.5 mg/L with relative standard deviation(RSD)of 6.8%were obtained after measuring 45 times the wastewater with COD value of 30 mg/L under a sampling interval of 400 s.The as-prepared electrochemical COD sensor possessed good promise in regular monitoring of COD,discharge of wastewater and industrial process control,with advantages such as a small sampling interval,mild reaction conditions and no requirement of toxic and harmful chemical reagents.

Objective:To explore the impacts of thermotherapy combined with gemcitabine on the biological behavior of tongue squamous cell carcinoma cells.Methods:Human tongue squamous cell carcinoma Tca8113 cells were divided into the control group (blank control), gemcitabine group, thermotherapy group (heated in an incubator at 43℃ for 1 h and then incubated at 37℃ for 24 h) and thermotherapy + gemcitabine group. The proliferation ability of Tca8113 cells was assessed by EdU staining and CCK-8 assay. Cell apoptosis and cell cycle of Tca8113 cells were detected by flow cytometry. The invasion of Tca8113 cells was determined by Transwell chamber assay. The expression levels of cyclin D1 (CyclinD1), Bcl-2-associated X protein (Bax), matrix metalloproteinase (MMP)-9, phosphorylated histone H2AX (γH2AX) and Nijmegen breakage syndrome 1 (NBS1) proteins in Tca8113 cells were measured by Western blot. The changes of tumor mass and volume were detected by xenograft tumor in vivo test in nude mice. Multi-group comparison was performed by one-way ANOVA. Two group comparison was conducted by SNK- q test. Results:Compared with the control group, EdU positive cell percentage, OD 450 value, invasive cell number, CyclinD1, MMP-9 and NBS1 protein expression of Tca8113 cells were decreased, whereas the apoptosis rate, the expression of Bax and γH2AX proteins were increased in the gemcitabine, thermotherapy and thermotherapy + gemcitabine groups ( q=4.45-72.06, all P<0.001). Compared with the control group, the proportion of G 0/G 1 phase cells was decreased, whereas the proportion of S and G 2/M phase cells was increased in the gemcitabine and thermotherapy + gemcitabine groups, the proportion of G 0/G 1 phase cells was decreased and the proportion of G 2/M phase cells was increased in the hyperthermia group ( q=10.36-61.09, all P<0.001). Compared with the gemcitabine and thermotherapy groups, EdU positive cell percentage, OD 450 value, G 0/G 1 phase cell proportion, invasive cell number, CyclinD1, MMP-9 and NBS1 protein expression of Tca8113 cells were decreased, whereas apoptosis rate, S, G 2/M phase cell proportion, Bax and γH2AX protein expression were increased in the thermotherapy + gemcitabine group ( q=4.45-28.73, all P<0.001). Xenograft tumor in vivo test in nude mice showed that the tumor volume and mass of nude mice in the gemcitabine, thermotherapy, and thermotherapy + gemcitabine groups were decreased compared with those in the control group ( q=5.58-73.02, all P<0.001). Compared with the gemcitabine and thermotherapy groups, the tumor volume and mass in the thermotherapy + gemcitabine group were decreased ( q=5.58-21.45, all P<0.001). Conclusion:The combination of thermotherapy and gemcitabine can inhibit the proliferation and invasion, block the cell cycle, and induce cell apoptosis of Tca8113 cells.

Hyperthermia, as an adjunct to radiotherapy and chemotherapy, can change the immune condition of tumor microenvironment and enhance the effect of tumor treatment without damaging normal tissues. Tumor-associated macrophages are the main immune cells in the tumor microenvironment, and there are two subtypes: M1 phenotype can inhibit the growth of tumor cells, and M2 phenotype can promote the occurrence and metastasis of tumor cells. Therefore, repolarization of M2 phenotype into M1 phenotype is a new research direction. In this paper, the mechanisms of hyperthermia and tumor-associated macrophage repolarization were reviewed based on the current research progress at home and abroad, aiming to provide novel ideas for tumor therapy.

Objective:To explore the association between the variability of triglyceride glucose index (TyG) and the risk of type 2 diabetes mellitus(T2DM).Methods:This study was a retrospective cohort study. A total of 22 929 community-dwelling elderly (aged≥60 years) who received annual health check-ups in Kunshan city of Suzhou Municipality during 2014 to 2021 were enrolled in the study. Fasting triglycerides and blood glucose were measured during annual physical check-ups and the TyG was calculated, the standard deviation of TyG measurements in three consecutive physical check-ups was used as the indicatior of TyG long-term variability. According to the quartile of TyG long-term variability, the study subjects were divided into four groups, namely Q 1 (0-0.14), Q 2 (>0.14-0.22), Q 3 (>0.22-0.33), Q 4 (>0.33-1.90). The outcome variable was the occurrence of T2DM. The relationship between TyG variability and T2DM incidence was analyzed by multivariate Cox regression. Results:In the study cohort 11 518 (50.2%) were females and the mean age was (67.42±5.35) years. By the end of follow-up, 2 934 cases of new T2DM were diagnosed, with an oveall incidence rate of 12.8%. After adjusting for multiple confounders and average TyG, long-term variability of TyG was significantly associated with T2DM risk ( HR=1.83, 95% CI: 1.51-2.20). The risk of T2DM in Q 4 group was significantly higher than that in Q 1 group ( HR=1.33, 95% CI: 1.19-1.47). Kaplan-Meier survival curve showed that long-term variability of TyG was significantly correlated with the cumulative risk of T2DM incidence ( P<0.001). Conclusions:TyG variability is an independent risk factor for T2DM, suggesting that attention should be paid not only to specific time-point TyG levels but also to TyG fluctuation for early identification of T2DM risk.