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 observe the safety and effectiveness of single dose intravenous infusion of tranexamic acid(TX-A)in dual level posterior lumbar interbody fusion(PLIF),and to explore the changes and trends in perioperative white blood cell(WBC),erythrocyte sedimentation rate(ESR),and C-reactive protein(CRP).Methods Between October 2020 and September 2022,46 patients with lumbar degenerative disease were treated with dual level PLIF,including 18 males and 28 females,with an average age of(60.24±10.68)years old,from 34 to 80 years old.They were divided into observation group and control group according to different treatment methods.There were 28 patients in the observation group,including 12 males and 16 females,with an average age of(61.04±9.03)years old.There were 3 cases with lumbar disc herniation(LDH),lumbar spinal stenosis(LSS)18 cases,lumbar spondylolisthesis(LS)7 cases.TXA(1 g/100 ml)was administered intravenously 15 min before skin incision after general anesthesia.The control group consisted of 18 patients,including 6 males and 12 females,with an average age of(59.00±13.04)years old.There were 5 cases with LDH,LSS 9 cases,LS 4 cases,and TXA was not used.The operation time,intraoperative bleeding volume,postoperative drainage volume,postoperative deep vein thrombosis(DVT),postoperative hospital stay,postoperative activated partial thromboplastin time(APTT),prothrombin time(PT),thrombin time(TT),fibrinogen(FIB),platelet(PLT),red blood cell(RBC),hemoglobin(HB),hematocrit(HCT),the first day,the fourth day,the seventh day and the last tested after operation WBC,ESR and CRP were recorded.Results The postop-erative wounds of the patients healed well and there was no DVT.46 patients were followed up from 3 to 6 months.The intraop-erative blood loss was 400.0(300.0,500.0)ml and the postoperative drainage was 260.0(220.0,450.0)ml in the observation group,which were lower than the control group[600.0(400.0,1000.0)ml,395.0(300.0,450.0)ml],P＜0.05.There was no significant difference between the two groups in operation time,postoperative hospital stay,postoperative APTT,PT,TT,FIB,PLT,RBC,HB,HCT,and postoperative WBC,ESR and CRP at different times(P＞0.05).Conclusion Single dose intravenous infusion of TXA can reduce the blood loss of bi-segmental PLIF,and has no significant effect on WBC,ESR and CRP after op-eration.

Objective:To evaluate the application of digital visualization in preoperative planning for surgical clearance of vertebral infection lesions following percutaneous vertebroplasty (PVP).Methods:A retrospective study was conducted to analyze the 13 patients with infectious spondylitis following PVP who had undergone one-stage posterior debridement and interbody bone grafting combined with instrumentation at Department of Spinal Surgery, Zhengzhou Orthopaedics Hospital from January 2016 to December 2022. They were 4 males and 9 females with an age of (71.4±6.5) years. Before surgery, the CT raw data of the patients were imported into software Mimics to reconstruct a three-dimensional model of the spine. After the distribution of bone cement in the model and its relationships with the vertebral plate, pedicle, articular process, and spinal cord were observed, a safe area for spinal canal surgery was designed. Intraoperative operations were carried out according to the preoperative planning. Surgical time, intraoperative blood loss, improvements in American Spinal Injury Association (ASIA) grading, and postoperative complications were recorded. The therapeutic efficacy was evaluated by comparisons of erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), visual analogue scale (VAS), and Oswestry disability index (ODI) between preoperation, 2 weeks and 3 months postoperation, and the last follow-up.Results:Surgery went on successfully in all the 13 patients according to the preoperative planning. The surgical time was (275.9±28.3) min and the intraoperative blood loss (865.4±183.0) mL. All patients were followed up for (24.7±9.4) months. The levels of ESR, CRP, VAS, and ODI at 2 weeks, 3 months and the last follow-up were significantly lower than those before surgery ( P<0.05). At the last follow-up, X-ray and CT examinations showed good positions of internal fixation and sufficient bone graft fusion. The ASIA grading recovered from preoperative D to E in 5 patients. No incision infection, sinus formation, worsening of neurological symptoms, loosening or rupture of internal fixation, or worsening of neurological dysfunction were found. Conclusion:With the assistance of 3D visualization, the spinal cord, bone cement, and debridement area can be visualized directly to reduce nerve injury complications so that a safe and effective preoperative planning can be made for surgical clearance of vertebral infection lesions following PVP.

This study was aimed at characterizing the variations in hemagglutinin(HA)and neuraminidase(NA)genes of influenza virus subtype A(H1N1)pdm09 isolated during the 2022-2023 influenza monitoring year in Shandong Province,to provide a scientific basis for influenza prevention and control.A total of 14 A(H1N1)pdm09 subtype influenza strains were se-lected randomly by city by the influenza monitoring network laboratory.The vaccine strains recommended by the WHO served as references for whole gene sequencing analysis.A fluorescence method was used to conduct neuraminidase inhibition experi-ments to evaluate drug sensitivity.The A(H1N1)pdm09 influenza virus in Shandong Province,2022-2023 belonged to the 5a.2a evolutionary cluster in the 6B.1A branch.Nucleotide sequence analysis indicated that the HA and NA genes were closely re-lated to the Northern Hemisphere vaccine strain A/Victoria/2570/2019 in the years 2021-2023,and showed homology of 98.5％to 98.7％and 98.8％to 99.1％,respectively.Amino acid sequence analysis revealed 20 amino acid sequence mutations in the HA protein,but only one virus strain was found to have antigen drift,and three virus strains showed loss of HA protein glycosylation sites.No mutations were found at important sites affecting NA enzymes.The neuraminidase inhibition experiment indicated viral sensitivity to anti-influenza drugs.In conclusion,the monitored virus strains had high overall homology with vac-cine strains but showed some amino acid variation.In the future,continued monitoring of the genetic variation characteristics of influenza viruses will be necessary to understand the risk of influenza epidemics,and the effectiveness of influenza vaccines and therapeutic drugs.

This study was aimed at understanding the pollution distribution pattern of avian influenza virus in the environ-ment in poultry related places in Shandong Province,to provide a scientific basis for the prevention,control,prediction,and early warning regarding human infection with avian influenza.From 2020 to 2023,6 523 environmental samples were collected in 16 cities in Shandong Province from four types of poultry-related places.Fluorescence quantitative PCR was used for nucleic acid testing of influenza A virus.Positive samples were further identified for the H5,H7,and H9 subtypes of avian influenza virus.The epidemiological characteristics of avian influenza viruses in the poultry related environment of Shandong Province were described,and inter-rate comparisons were performed with the x2 test.During 2020-2023,6 523 environmental samples were collected,and 1 007 cases positive for avian influenza virus were detected,with a positivity rate of 15.44％.H5,H7,and H9 subtypesand mixed infections were detected.H9 was the main subtype(88.48％)in positive specimens.A significant difference in positivity rates was observed among regions(x2=431.956,P＜0.001),and the highest positivity rate was 28.93％.Significant differences in positivity rates were observed among monitoring sites(x2=304.604,P＜0.001),sample types(x2=109.678,P＜0.001),and quarters(x2=64.963,P＜0.001).The positive detection rate was highest at monitoring sites in urban and rural live poultry markets(20.12％),and the positive detection rate of samples collected by wiping meat cut-ting board surfaces was higher than that of other samples(22.56％).The peak positive detection rate occurred in spring(20.31％).Widespread contamination with avian influenza virus was observed in poultry environments in Shandong Prov-ince.The H9 subtype,the main pathogen,coexisted with H5 and H7 subtypes,thus posing a risk of human infection with avian influenza.Therefore,prevention and control of avian influenza must be strengthened in key seasons,areas,places,and links.

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.

The global morbidity and mortality of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection are gradually decreasing,but the elderly people are still at higher risk of death than the general population,especially for those with Alzheimer's disease(AD).AD is a slowly progressing degenerative disease of the nervous system,and is the most common type of dementia.Its neuropathological features include overproduction and clea-rance imbalance of amyloid β-protein and overphosphorylated tau protein leading to neurofibrillary tangle.People with AD are more susceptible to be infected with SARS-CoV-2,likewise,the virus can also cause AD in those who are infected.After SARS-CoV-2 infection,it affects AD through immune response,inflammatory response,cell aging,DNA damage reaction,autophagy disorder,choroidal homeostasis disorder,over-activation of renin-angio-tensin system,and oxidative stress.This article mainly reviews the research progress in the effect of SARS-CoV-2 infection on AD.

Background::Although overnight fasting is recommended prior to endoscopic retrograde cholangiopancreatography (ERCP), the benefits and safety of high-carbohydrate fluid diet (CFD) intake 2 h before ERCP remain unclear. This study aimed to analyze whether high-CFD intake 2 h before ERCP can be safe and accelerate patients’ recovery.Methods::This prospective, multicenter, randomized controlled trial involved 15 tertiary ERCP centers. A total of 1330 patients were randomized into CFD group ( n = 665) and fasting group ( n = 665). The CFD group received 400 mL of maltodextrin orally 2 h before ERCP, while the control group abstained from food/water overnight (>6 h) before ERCP. All ERCP procedures were performed using deep sedation with intravenous propofol. The investigators were blinded but not the patients. The primary outcomes included postoperative fatigue and abdominal pain score, and the secondary outcomes included complications and changes in metabolic indicators. The outcomes were analyzed according to a modified intention-to-treat principle. Results::The post-ERCP fatigue scores were significantly lower at 4 h (4.1 ± 2.6 vs. 4.8 ± 2.8, t = 4.23, P <0.001) and 20 h (2.4 ± 2.1 vs. 3.4 ± 2.4, t= 7.94, P <0.001) in the CFD group, with least-squares mean differences of 0.48 (95% confidence interval [CI]: 0.26–0.71, P <0.001) and 0.76 (95% CI: 0.57–0.95, P <0.001), respectively. The 4-h pain scores (2.1 ± 1.7 vs. 2.2 ± 1.7, t = 2.60, P = 0.009, with a least-squares mean difference of 0.21 [95% CI: 0.05–0.37]) and positive urine ketone levels (7.7% [39/509] vs. 15.4% [82/533], χ2 = 15.13, P <0.001) were lower in the CFD group. The CFD group had significantly less cholangitis (2.1% [13/634] vs. 4.0% [26/658], χ2 = 3.99, P = 0.046) but not pancreatitis (5.5% [35/634] vs. 6.5% [43/658], χ2 = 0.59, P = 0.444). Subgroup analysis revealed that CFD reduced the incidence of complications in patients with native papilla (odds ratio [OR]: 0.61, 95% CI: 0.39–0.95, P = 0.028) in the multivariable models. Conclusion::Ingesting 400 mL of CFD 2 h before ERCP is safe, with a reduction in post-ERCP fatigue, abdominal pain, and cholangitis during recovery.Trail Registration::ClinicalTrials.gov, No. NCT03075280.

AIM To analyze the metabolites of nobiletin in rats in vivo based on characteristic ions.METHODS Ten rats were assigned into administration group and control group,and given intragastric administration of the 0.5％CMC-Na suspension of nobiletin(250 mg/kg)and 0.5％CMC-Na solution,respectively,after which plasma,urine and feces were collected,solid phase extraction method was adopted in pretreatment,UHPLC-HRMS analysis was performed.The candidate metabolites were systematically described according to diagnostic product ions,chromatographic retention time,accurate molecular weight and neutral loss fragments,after which accurate metabolites were obtained in the established metabolite data set with-CH3(m/z 15)characteristic ions as a baits.RESULTS A total of 64 metabolites were identified,whose main metabolic pathways were glucuronidation,sulfation,hydrogenation and their compound reactions.CONCLUSION This experiment elucidates the metabolites of nobiletin in rats in vivo,which provides a new reference for its further development.

Spinocerebellar ataxia (SCA) is a group of progressively aggravated neurodegenerative disease with autosomal dominant inheritance. Cerebellar ataxia is the core symptom, which may be accompanied by pyramidal tract signs, extrapyramidal signs, cognitive dysfunction and peripheral neuropathy. Although SCA can be accurately diagnosed by genetic testing, treatment is still difficult. We review the pathogenesis and therapeutic targets of SCA in recent years, in terms of genetic or gene regulation abnormalities, disruption of protein quality control (PQC) network, disruption of energy homeostasis, stability maintenance of PQC system, maintenance of cerebellar Purkinje cell function, and regulation of neuroinflammation, so as to promote the transformation of preclinical research into human therapy.