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.

Abstract The harm of head injury in skateboarding is more serious. The common injury cause is fall, collision, high speed impact. The primary types of injury include skull fracture, subdural hemorrhage, brain laceration contusion and concussion. Older children and adolescents, males, longboard, inappropriate sports venue are important risk factors for severe traumatic brain injury. Designing special skateboard parks and wearing protective equipment (helmets) can effectively reduce the incidence and severity of head injuries. The occurrence of injury can be reduced by adopting both legislation and education measures.

Fluorescence anisotropy(FA)analysis has many advantages such as no requirement of separation,high throughput and real-time detection,and thus has been widely used in many fields,including biochemical analysis,food safety detection,environmental monitoring,etc.However,due to the small volume or mass of the target,its combination with the fluorescence probe cannot produce significant signal change.To solve this issue,researchers often use nanomaterials to enhance the mass or volume of fluorophore to improve the sensitivity.Nevertheless,this FA amplification strategy also has some disadvantages.Firstly,nanomaterials are easy to quench fluorescence.As a result,the FA value is easily influenced by light scattering,which reduces the detection accuracy.Secondly,fluorescent probes in most methods require complex modification steps.Therefore,it is necessary to develop new FA probes that do not require the amplification of volume and mass or modification.As a new kind of nanomaterials,luminescent metal-organic framework(MOF)has a large volume(or mass)and strong fluorescence emission.It does not require additional signal amplification materials.As a consequence,it can be used as a potential FA probe.This study successfully synthesized a lanthanide metal organic framework(Ce-TCPP MOF)using cerium ion(Ce3+)as the central ion and 5,10,15,20-tetra(4-carboxylphenyl)porphyrin(H2TCPP)as the ligand through microwave assisted method,and used it as a novel unmodified FA probe to detect phosphate ions(Pi).In the absence of Pi,Ce-TCPP MOF had a significant FA value(r).After addition of Pi,Pi reacted with Ce3+in MOF and destroyed the structure of MOF into the small pieces,resulting in a decrease in r.The experimental results indicated that with the increase of Pi concentration,the change of the r of Ce-TCPP MOF(Δr)gradually increased.The Δr and Pi concentration showed a good linear relationship within the range of 0.5-3.5 μmol/L(0.016-0.108 mg/L).The limit of detection(LOD,3σ/k)was 0.41 μmol/L.The concentration of Pi in the Jialing River water detected by this method was about 0.078 mg/L,and the Pi value detected by ammonium molybdate spectrophotometry was about 0.080 mg/L.The two detection results were consistent with each other,and the detection results also meet the ClassⅡwater quality standard,proving that this method could be used for the detection of Pi in complex water bodies.

The incidence of intrahepatic cholangiocarcinoma (ICC) continues to rise, and there are no effective drugs to treat it. The immune microenvironment plays an important role in the development of ICC and is currently a research hotspot. Icaritin (ICA) is an innovative traditional Chinese medicine for the treatment of advanced hepatocellular carcinoma. It is considered to have potential immunoregulatory and anti-tumor effects, which is potentially consistent with the understanding of "Fuzheng" in the treatment of tumor in traditional Chinese medicine. However, whether ICA can be used to treat ICC has not been reported. Therefore, in this study, sgp19/kRas, an in situ ICC mouse model with intact immune system, was selected to evaluate the efficacy of ICA in the treatment of ICC in vivo for the first time, and the effects of ICA on the tumor immune microenvironment of ICC mice were analyzed by flow cytometry. This experiment was approved by the Experimental Animal Ethics Committee of Capital Medical University (approval number: AEEI-2023-138). In this study, sgp19/kRas ICC mouse model was treated with oral gavage of 100 mg·kg^-1 ICA. We found that ICA significantly inhibited tumor growth and tumor cell proliferation in the sgp19/kRas ICC mouse model after 3 weeks of treatment. Flow cytometry analysis indicated that ICA treatment markedly reduced the proportion of M2 macrophages and increased the number of CD3⁺CD4⁺ T cells. In vitro experiments demonstrated that ICA promoted macrophage polarization towards the M1 phenotype while inhibiting polarization towards the M2 phenotype. Furthermore, transcriptomic analysis suggested that ICA enhanced Toll-like receptor 9 (TLR9) expression, influencing macrophage nitric oxide metabolism synthesis pathways and receptor-related activities, thereby regulating macrophage polarization. In summary, this study demonstrates that ICA treatment significantly delays tumor progression in sgp19/kRas ICC mouse models. Mechanistically, ICA may achieve its anti-ICC effects by upregulating TLR9 receptor expression levels, promoting macrophage polarization towards the M1 phenotype, and altering the tumor immune microenvironment.

Objective Pancreatic cancer(PC)is a malignant tumor of the digestive tract that is difficult to diagnose early,easily metastasizes and relapses,and resistant to conventional chemotherapy.PC is a very difficult disease to treat.The key regulatory factors of PC resistance,such as epithelial-mesenchymal transition phenotypic cells,tumor stem cells,and miRNAs,have been reviewed in the past few years,and some new regulatory factors have been discovered as supplements.This review mainly focuses on the characteristics and properties of the key regulatory factors of PC chemotherapy resistance including long noncoding RNAs,nuclear factor KB and exosomes,drug resistance mechanisms,and treatment related strategies,and future treatment directions were predicted.

Objective To investigate the protective effect of dexmedetomidine(Dex)pretreatment on myocardial ischemia-reperfusion mice and the effect of Nod-like receptor protein 3(NLRP3)inflammatory signaling pathway.Methods C57BL/6J mice were randomly divided into sham group(only threading without ligation),model group(recovery after ligation of left anterior descending coronary artery),positive group(modeling after intraperitoneal injection of 1 mg·kg-1 trimetazidine),Dex group(modeling after intraperitoneal injection of 20 μg·kg-1 dexmedetomidine),MCC950 group(modeling after intraperitoneal injection of 10 mg·kg-1 NLRP3 inhibitor MCC950),12 mice in each group.Cardiac function indexes were detected at 24 h after reperfusion,the expression level of related proteins in myocardial tissue was detected by Western blot,enzyme-linked immunosorbent assay(ELISA)was used to detect the expression level of serum factor,myocardial antioxidant index was detected by kit method,and apoptosis was detected by Tunel method.Results The NLRP3 protein expression levels of sham group,model group,positive group,Dex group and MCC950 group were 0.31±0.05,1.06±0.07,0.52±0.05,0.65±0.07 and 0.39±0.04,respectively;the expression levels of apoptosis-associated granuloid protein(ASC)were 0.27±0.08,0.88±0.09,0.46±0.05,0.59±0.07 and 0.34±0.04,respectively;CK-MB levels were(25.64±2.94),(102.08±7.04),(49.61±7.70),(60.86±5.24)and(63.24±5.38)U·L-1,respectively;IL-6 levels were(104.78±10.73),(231.54±15.56),(158.20±16.54),(165.10±14.77)and(141.17±14.08)pg·mL-1,respectively;Tunel positive cell rates were(4.34±0.16)％,(25.98±1.58)％,(8.74±0.93)％,(11.06±1.07)％and(9.19±0.88)％,respectively.Sham group were compared with model group;Dex group and MCC950 group were compared with model group,the above indexes were statistically significant(all P＜0.05).Conclusion Dexmedetomidine preconditioning may prevent ischemia-reperfusion myocardial injury by inhibiting NLRP3/ASC/caspase-1 inflammatory pathway,inflammatory response and myocardial cell apoptosis.

AIM: To observe the imaging characteristics of the affected eyes of patients with central serous chorioretinopathy(CSC)of different ages and their asymptomatic fellow eyes.METHODS: Retrospective study. A total of 76 cases(88 eyes)of CSC patients diagnosed in the ophthalmology department of our hospital from April to September, 2023 and 35 cases(35 eyes of asymptomatic fellow eyes of patients with unilateral CSC)were selected for the study. According to age, they were divided into young and middle-aged groups(<40 years old), middle-aged groups(40-50 years old)and middle-aged and elderly groups(>50 years old). The imaging features of the affected eyes of CSC patients of different ages and their asymptomatic fellow eyes were observed.RESULTS: The subfoveal choroidal thickness(SFCT)of CSC eyes in the young and middle-aged patients(487.30±83.33 μm)was significantly greater than that of the middle-aged group(414.17±96.02 μm, P<0.05)and the middle-aged and elderly group(409.4±107.42 μm, P<0.05). The incidence of choroidal neovascularization(CNV)in CSC patients of the middle-aged and elderly group was significantly higher than that in the young and middle-aged group(P<0.0167). The SFCT of the asymptomatic fellow eye of the unilateral CSC patient in the young and middle-aged group(511.29±40.89 μm)was significantly larger than that of the middle-aged and elderly group(364.76±82.26 μm, P<0.05). Among them, the vortex vein anastomosis rate in eyes with CSC is higher than 90%, and vortex vein anastomosis or dilatation is present in all asymptomatic fellow eyes of CSC patients.CONCLUSION: There are differences in the imaging manifestations of CSC-affected eyes and their asymptomatic fellow eyes of different age groups. SFCT is generally thickened and gradually becomes thinner with the growth of age. The incidence of CNV in CSC-affected eyes is the highest in the middle-aged and elderly group. In addition, vortex vein anastomosis and dilatation are common in CSC-affected eyes and asymptomatic fellow eyes.

Objective Studies on the relationship between iodine,vitamin A(VA),and vitamin D(VD)and thyroid function are limited.This study aimed to analyze iodine and thyroid-stimulating hormone(TSH)status and their possible relationships with VA,VD,and other factors in postpartum women. Methods A total of 1,311 mothers(896 lactating and 415 non-lactating)from Hebei,Zhejiang,and Guangxi provinces were included in this study.The urinary iodine concentration(UIC),TSH,VA,and VD were measured. Results The median UIC of total and lactating participants were 142.00 μg/L and 139.95 μg/L,respectively.The median TSH,VA,and VD levels in all the participants were 1.89 mIU/L,0.44 μg/mL,and 24.04 ng/mL,respectively.No differences in the UIC were found between lactating and non-lactating mothers.UIC and TSH levels were significantly different among the three provinces.The rural UIC was higher than the urban UIC.Obese mothers had a higher UIC and a higher prevalence of excessive TSH.Higher UICs and TSHs levels were observed in both the VD deficiency and insufficiency groups than in the VD-sufficient group.After adjustment,no linear correlation was observed between UIC and VA/VD.No interaction was found between vitamins A/D and UIC on TSH levels. Conclusion The mothers in the present study had no iodine deficiency.Region,area type,BMI,and VD may be related to the iodine status or TSH levels.

Objective To compare the outcomes of transplant kidneys and patient survival between simultaneous pancreas-kidney transplantation(SPKT)recipients and deceased donor kidney transplant(DDKT)recipients in patients with type 2 diabetes mellitus(T2DM)complicated with end-stage renal disease(ESRD),and to analyze the risk factors affecting patient survival post-SPKT.Methods Clinical and prognostic data of patients who underwent kidney transplantation from January 27,2003,to January 1,2021,were retrieved from the United Network for Organ Sharing(UNOS)database.A total of 50 230 cases were selected based on inclusion criteria,with 48 669 cases in DDKT group and 1561 cases in SPKT group.Kaplan-Meier analysis was employed to compare transplant kidney and patient survival between the two groups,and propensity score matching(PSM)was utilized to balance confounding factors between the groups.Cox regression model was used to analyze independent risk factors affecting patient survival post-SPKT.Results Compared with DDKT group,recipients in SPKT group had a younger median age(P<0.001),a higher proportion of males(P<0.001),lower BMI(P<0.001),shorter dialysis and transplant waiting times(P<0.001),a higher percentage of private medical insurance(P<0.001),a lower proportion of previous transplants(P<0.001),a younger age at diabetes diagnosis(P<0.001),and a lower incidence of peripheral vascular disease(P=0.033).Compared with DDKT group,the donors in SPKT group had a younger median age(P<0.001),a higher proportion of males(P<0.001),lower BMI(P<0.001),and a lower prevalence of hypertension and diabetes history(P<0.001).In terms of transplant-related factors,the SPKT group had a shorter donor kidney cold ischemia time(P<0.001),a higher degree of HLA mismatch(P<0.001),and a lower Kidney Donor Profile Index(KDPI)(P<0.001)when compared with DDKT group.The SPKT group had lower serum creatinine levels at discharge(P<0.001),lower rates of postoperative delayed graft function(DGF)and acute rejection(AR)(P<0.001),but longer hospital stays(P<0.001)when compared with DDKT group.Kaplan-Meier survival analysis curves,both original and after propensity score matching(PSM),consistently showed significantly higher transplant kidney and patient survival rates in SPKT group compared with DDKT group(P<0.001).Cox regression model analysis indicated that recipient age,recipient race,donor age,and donor kidney cold ischemia time were independent risk factors influencing patient survival post-SPKT.Conclusions For ESRD patients with T2DM,SPKT offers improved long-term graft and patient survival rates compared with DDKT.Recipient age,recipient ethnicity,donor age,and cold ischemia time for the donor's kidney are independent risk factors affecting post-SPKT patient survival.

Objective To investigate the expression of prolyl 4-hydroxylase β-polypeptide(P4HB)in glioblastoma multiforme(GBM)and its impact on clinical prognosis,as well as on the proliferation and migration of U87 cells.Methods(1)According to the Cancer Genome Atlas(TCGA)database,GTEx database and GEPIA2 database,the difference expression of P4HB in GBM and normal brain tissues were analyzed by R software.(2)A total of 52 patients with GBM who underwent surgical treatment from February 2017 to December 2019 were collected from Department of Neurosurgery,the Second People's Hospital of Guiyang.The normal brain tissues of 10 patients were selected as controls.Immunohistochemical method was used to detect the expression level of P4HB in tumor tissues and normal tissues.The Kaplan-Meier method with the log-rank test was employed for survival analysis.Receiver operating characteristic(ROC)curve was used to analyze the predictive valuable of P4HB expression in survival rate of GBM.Univariate and multivariate Cox regression analysis were used to identify the expression of P4HB and related clinicopathological factors affecting the survival and prognosis of the patients.(3)Human GBM U87 cells were randomly assigned into three groups:control group,NC-siRNA group and P4HB-siRNA group.P4HB expression was interfered with by the transfection of siRNA in P4HB-siRNA group.Real-time quantitative polymerase chain reaction(qRT-PCR)was used to detect the content of P4HB mRNA in U87 cells.Cell counting kit-8(CCK-8)and immunofluorescence assay were used to analyze the effects of P4HB on the proliferation of U87 cells.Scratch test was used to analyze the effects of P4HB on cell migration.Results The expression of P4HB was significantly upregulated in GBM tissues compared with normal brain tissues(P<0.05).The γδ T cells(r=-0.227)and follicular helper T cells(r=-0.226)were negatively correlated with the expression of P4HB,while natural killer cell(r=0.417),macrophages(r=0.374),neutrophils(r=0.344),and immature dendritic cells(r=0.263)were positively correlated with the expression of P4HB.Kaplan-Meier survival analysis showed that the progression-free survival and disease-specific survival of GBM patients with high P4HB expression were significantly lower than those with low expression(P<0.05).ROC curve showed that the area under the curve(AUC)of P4HB in predicting overall survival rate of GBM patients was 0.982,and 1-year,3-year,and 5-year survival was 0.655,0.724,0.861,respectively.The immunohistochemistry results suggested that P4HB protein was significantly highly expressed in GBM tumors.Survival analysis indicated that high expression of P4HB was associated with bad prognosis in GBM patients(P<0.05).Multivariate Cox regression analysis indicated that high expression of P4HB and TERT promoter mutations were the independent prognostic risk factors for GBM(P<0.05).Compared with control group and NC-siRNA group,the expression levels of P4HB were decreased significantly after transfected with siRNA in U87 cells of P4HB-siRNA group(P<0.01),and the proliferation ability and the wound healing rate were decreased significantly in P4HB-siRNA group(P<0.001).Conclusions P4HB is significantly highly expressed in GBM,which indicates that the prognosis of patients is poor.Knockout of P4HB could inhibit cellular proliferation and migration of GBM U87 cells.P4HB may be used as the relevant predictive marker and potential therapeutic target in GBM.