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 evaluate the application of a two-stage sequential nutritional therapy combined with functional exercise in the preoperative prehabilitation of patients with high-output intestinal fistula(HIF).Methods:A total of 164 HIF patients scheduled for definitive fistula resection in the Department of General Surgery,Eastern Theater Command General Hospital from March 2023 to March 2025 were prospectively enrolled.They were randomly assigned to a control group or an intervention group at a 1:1 ratio,with 82 patients in each group.The control group received conventional nutritional support and basic functional exercise,while the intervention group underwent a two-stage sequential nutritional therapy combined with graded functional exercise.Nutritional indicators,inflammatory markers,functional status,and postoperative recovery were compared between the two groups at 28 days before surgery,1 day before surgery,and 1,3,and 7 days after surgery.Results:On the day before surgery,the nutritional indicators in the intervention group,including albumin[(36.8±4.1)g/L],prealbumin[(213.5±42.1)mg/L],and total protein[(69.3±6.1)g/L],were all significantly higher than those in the control group[albumin(33.1±3.9)g/L,prealbumin(163.2±37.6)mg/L,total protein(63.7±5.9)g/L],with P<0.001.The energy compliance rates on the 21st day before surgery and the day before surgery in the intervention group(85.2%,92.8%)were significantly higher than those in the control group(62.5%,72.4%),with P<0.001.The 6-minute walk distance(6MWD)in the intervention group on the day before surgery and on the 7th day after surgery[(385.1±55.2)m,(346.3±48.4)m]was significantly greater than that in the control group[(315.3±60.7)m,(298.3±51.1)m],with P<0.001.On the 1st day after surgery,the inflammatory markers in the intervention group[CRP(98.7±35.2)mg/L,IL-6(45.3±12.5)pg/mL,PCT(1.2±0.5)ng/mL]were all significantly lower than those in the control group[CRP(152.4±48.6)mg/L,IL-6(89.6±25.4)pg/mL,PCT(2.8±0.9)ng/mL],with P<0.001.Additionally,the time to first ambulation after surgery[(16.8±4.2)h],time to first flatus[(52.4±14.5)h],and ICU stay duration[(3.1±1.6)d]in the intervention group were all significantly shorter than those in the control group,with P<0.001 Conclusion:The two-stage sequential nutritional therapy combined with functional exercise significantly improves the attainment of nutritional targets,suppresses systemic inflammatory response,enhances muscle reserve and exercise tolerance,and effectively shortens the postoperative recovery period in HIF patients.These findings support the use of this combined approach as a targeted and feasible model for preoperative prehabilitation,demonstrating substantial clinical application value.

ObjectiveTo study the pharmacological substances and mechanisms through which sesquiterpene ZH-13 from Aquilariae Lignum Resinatum improves neuroinflammation. MethodsBV-2 microglial cells were stimulated with lipopolysaccharide （LPS） to induce neuroinflammation. The cells were divided into the normal group， the model group， and the ZH-13 low- and high-dose treatment groups （10， 20 μmol·L^-1）. The model group was treated with 1 μmol·L^-1 LPS. Cell viability was assessed using the cell proliferation and activity assay （CCK-8 kit）. Nitric oxide （NO） release in the cell supernatant was measured using a nitric oxide kit （Griess method）. The mRNA expression levels of interleukin-1β （IL-1β）， tumor necrosis factor-α （TNF-α）， inducible nitric oxide synthase （iNOS）， and interleukin-6 （IL-6） were detected by real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）. The phosphorylation of mitogen-activated protein kinase （MAPK） pathway proteins was assessed by Western blot. ResultsCompared with the model group， ZH-13 dose-dependently reduced NO release from BV-2 cells under LPS stimulation （P<0.05， P<0.01）. In the 20 μmol·L^-1 ZH-13 treatment group， the mRNA expression levels of IL-1β， TNF-α， iNOS， and IL-6 were significantly reduced compared to the model group （P<0.05， P<0.01）. In both the low- and high-dose ZH-13 groups， the expression of the inflammatory factor TNF-α and the phosphorylation of c-Jun N-terminal kinase （JNK） in the upstream MAPK pathway were significantly reduced （P<0.05）. After stimulation with the JNK agonist anisomycin （Ani）， both low- and high-dose ZH-13 treatment groups showed reduced phosphorylation of JNK proteins compared to the Ani-treated group （P<0.01）. ConclusionThe sesquiterpene compound ZH-13 from Aquilariae Lignum Resinatum significantly ameliorates LPS-induced neuroinflammatory responses in BV-2 cells by inhibiting excessive JNK phosphorylation and reducing TNF-α expression. These findings elucidate the pharmacological substances and mechanisms underlying the sedative and calming effects of Aquilariae Lignum Resinatum.

This study was aimed at investigating the effects of demethylase fat mass and obesity-associated protein(FTO)and methyltransferase methyltransferase like protein 3(METTL3),key molecules in N6-methyladenosine(m6A)modification,on the replication and proliferation of Japanese encephalitis virus(JEV).Recombinant lentiviruses were generated by packaging the FTO and green fluorescent protein into lentiviral vectors.Neuro2a cells,a mouse neuroblastoma cell line,were infected with the lentivirus,and stable FTO-expressing cell lines were obtained through puromycin selection.Successful overexpression of FTO was confirmed through fluorescence microscopy,real-time quantitative PCR,and western blot analysis.When Neuro2a cells overexpressing FTO were infected with JEV,the overexpression of FTO decreased JEV replication in the cells,and increased the expression of interferon(IFN)and related molecules.Additionally,treatment of JEV-infected Neuro2a cells with the METTL3-specific inhibitor STM2457 resulted in a dose-dependent decrease in JEV replication and viral protein expression.These findings suggested that lowering m6A methylation levels inhibits JEV replication,thus shedding light on the regulatory role of methylation modification in JEV replication.

Objective To evaluate the effects of transcatheter aortic valve replacement(TAVR)on left ventricular reverse remodeling(LVRR)and outcomes in patients with mixed aortic valve disease(MAVD)and predominant aortic stenosis(AS).Methods Patients undergoing TAVR at our center between January 2020 and December 2022 were enrolled consecutively.Propensity score matching(PSM)(1∶1 ratio)was used to reduce selection bias.Transthoracic echocardiography(TTE)was used to monitor left ventricular ejection fraction(LVEF)and other structural parameters over time.The study outcome was a composite of cardiovascular death and rehospitalization due to cardiovascular causes.Linear mixed-effects models and logistic regression were utilized for comparing echocardiographic changes across groups and identifying independent risk factors for no-LVRR,respectively.Results After PSM,126 patients were included.MAVD group exhibited larger structural parameters(left ventricular end-systolic/end-diastolic diameter and volume,left ventricular mass index)and a lower left ventricular ejection fraction(LVEF)(all P＜0.05).However,more pronounced improvements in left ventricular structure and hemodynamics were observed during follow-up.Multivariate logistic regression analysis indicated that the left ventricular mass index(LVMI)was an independent predictor of left ventricular reverse remodeling(LVRR)after TAVR,whereas persistent moderate or greater mitral regurgitation(MR)and paravalvular leak(PVL)significantly reduced the incidence of LVRR.During a median follow-up period of 23 months,a total of 31 endpoint events occurred,and there was no statistically significant difference in long-term prognosis between the two groups(Log-rank P=0.330).Conclusions Compared to patients in the AS group,those in the MAVD group exhibited more severe left ventricular remodeling before TAVR.However,more significant LVRR was observed during postoperative follow-up.Additionally,the long-term prognosis was comparable between the two groups.

Aim To investigate the therapeutic effects of a newly developed Tadalafil tablets on pathological myocardial hypertrophy induced by abdominal aortic constriction(AAC)in rats,as well as its influence on the activation of the NF-κB signaling pathway in myo-cardial cells.Methods SD rats were randomly divid-ed into 4 groups:the sham operation group(Sham),the model group(AAC),the tadalafil new tablet treat-ment group(N-Tad,5 mg·kg-1),and the positive control drug treatment group(Cialis,10 mg·kg-1g).The AAC model group and treatment group rats under-went blunt dissection and constrictive ligation of the abdominal aorta at the left renal artery branch point during surgery,while the Sham group rats only had their arteries separated without any constrictive liga-tion.Rats in the treatment groups received either N-Tad or Cialis via gavage three days after modeling,while rats in the sham group and the model group re-ceived physiological saline daily for 8 weeks.Small an-imal ultra-high-resolution echocardiography and hemo-dynamic assessment were applied to evaluate left ven-tricular function in each group of rats,and the calcula-tion of the left ventricular mass index was conducted.By employing Western blot and RT-PCR.we assessed the impact of this treatment on the expression of the hy-pertrophy factor atrial natriuretic peptide(ANP),phosphorylated NF-κB p65 protein(p-NF-κB p65),and phosphorylated IκB-α in the left heart tissue of rats and in H9c2 cardiomyocytes.Results Compared to the Sham group,the AAC rats exhibited a significant decrease in left heart function,an increase in left ven-tricular mass index,and a notable increase in ANP and p-p65 expression in the left heart tissue(P＜0.05).Both N-Tad and Cialis treatments could significantly enhance left ventricular function,decrease left ventric-ular mass index,and inhibit the expression of ANP and phosphorylated NF-κB p65 in rats with myocardial hy-pertrophy(P＜0.05).Notably,the therapeutic effect of low-dose N-Tad was comparable to that of high-dose Cialis.At the cellular level,Tadalafil significantly in-hibited the activation of the NF-κB signaling pathway and reduced the expression of associated proteins in H9c2 cardiomyocytes.Conclusions N-Tad can sig-nificantly inhibit p65 and IκB-α phosphorylation,and the activation of the NF-κB signaling pathway,reduce ANP expression,and improve pathological myocardial hypertrophy,as well as mitigate left heart function damage caused by abdominal aortic constriction.

Objective To develop dynamic prediction models based on multiple postnatal time points to support early diagnosis and individualized intervention for bronchopulmonary dysplasia(BPD)in preterm infants with gestational age<32 weeks.Methods Clinical data of 472 preterm infants with gestational age<32 weeks admitted to the Second Xiangya Hospital of Central South University between January 2016 and November 2020 were retrospectively analyzed.Multivariable logistic regression was applied to develop five independent prediction models at postnatal days 1,7,14,21,and 28.The performance of the models was assessed using the area under the receiver operating characteristic curve(AUC)and the Hosmer-Lemeshow test.Results Baseline characteristics such as gestational age and birth weight differed significantly between the BPD group(n=147)and the non-BPD group(n=325)(P<0.05).Predictors of BPD evolved across time points:on day 1,key predictors included gestational age,birth weight,Score for Neonatal Acute Physiology II(SNAP-II),invasive mechanical ventilation,and fraction of inspired oxygen>30%;by day 7,additional variables emerged,including fasting duration>2 days,mean feeding advancement rate<8.5 mL/(kg·d),neonatal respiratory distress syndrome,apnea of prematurity,and positive sputum culture;from day 14 onward,nutrition-and treatment-related indicators were incorporated additionally.The models demonstrated good discrimination at postnatal days 1,7,14,21,and 28,with AUCs of 0.917,0.927,0.939,0.944,and 0.968,respectively,and good calibration(Hosmer-Lemeshow P>0.05).Internal validation showed AUCs ranging from 0.899 to 0.958,indicating robust performance.Conclusions Dynamic postnatal prediction models incorporating indicators spanning perinatal factors,respiratory support,nutritional management,and therapeutic interventions demonstrate high predictive performance and facilitate dynamic risk assessment for BPD in preterm infants with gestational age<32 weeks.

Objective To summarize the clinical and genetic characteristics of children with sodium taurocholate co-transporting polypeptide(NTCP)deficiency.Methods Clinical data of children with NTCP deficiency diagnosed and treated at the First People's Hospital of Yunnan Province from July 2022 to March 2025 were retrospectively analyzed.Results A total of 14 children were included(6 males,8 females),all with normal growth and development.Reasons for initial consultation included elevated serum bile acids in 7 cases,jaundice in 4 cases,cholestatic hepatitis in 1 case,and one case each of pneumonia and cow's milk protein allergy.At the first visit,all patients had elevated serum total bile acids beyond the normal range,with a mean of 152.5 μmol/L.Elevated alanine aminotransferase was observed in 1 case,elevated aspartate aminotransferase in 2 cases,and elevated total bilirubin in 10 cases.Genetic sequencing revealed that all children carried the homozygous SLC10A1 variant c.800C>T(p.Ser267Phe),classified as likely pathogenic.Conclusions NTCP deficiency often lacks obvious clinical symptoms and signs.Some children present with transient hyperbilirubinemia,cholestasis,or other liver function abnormalities.Persistent isolated elevation of serum bile acids warrants suspicion for this disease.Biallelic pathogenic variants in SLC10A1 constitute the basis for definitive diagnosis.There is no specific treatment for this disease,and management is mainly symptomatic.

Hepatocellular carcinoma(HCC)is difficult to detect in its early stages and current treatment methods are associated with significant side effects and a high risk of developing drug resistance.This study aims to investigate the effect of phycocyanin(PC)on the apoptosis of human HCC HepG2 cells and its potential mechanism.HepG2 cells were treated with PC at concentrations of 0.1,0.25,0.5,1,2.5,5,and 10 μg/mL for 12 h,and with 10 μg/mL PC and 2.5 μmol/L Wip1 inhibitor(Wip1i)alone or in combination for 12 and 24 h,respectively.Cell proliferation levels were assessed using the CCK-8 cell proliferation-toxicity assay kit.Apoptosis levels were measured by Annexin V-FITC/Propidium Iodide double staining combined with flow cytometry.TMT(Tandem Mass Tag)proteomics quantitative technol-ogy was applied to analyze differential protein expression.Western blotting was used to detect the expres-sion levels of Wip1,p53,and phosphorylated-p53(Ser15)proteins.The CCK-8 assay revealed that PC effectively inhibited HepG2 cell proliferation in a concentration-dependent manner,with a half-maximal inhibitory concentration(IC50)of 19.37 μg/mL.Flow cytometry results showed that PC significantly in-duced apoptosis,with an apoptosis rate of 30.40％.Quantitative proteomics analysis indicated that PC induced activation of the p53 pathway.The CCK-8 assay showed that Wip1i enhanced the cytotoxic effect of PC on HepG2 cells.Western blotting confirmed that PC inhibited Wip1 expression,induced p53 pro-tein phosphorylation,and promoted the expression of total p53 protein.Additionally,Wip1i further en-hanced PC-mediated activation of the p53 pathway,increasing the expression of p53 and pP53(S15).In conclusion,PC may induce apoptosis by inhibiting the activity of the p53 negative regulator Wip1,thereby promoting apoptosis through the Wip1/p53 pathway.

Objective To explore the effects of the disinfection port position and diameter and disinfectant concentration on the in-situ decontamination of the flow field-based biosafety high efficiency particulate air filter device with the computational fluid dynamics(CFD)method.Methods ANSYS DesignModeler was used to construct five models for the high efficiency particulate air filter device with the disinfection port at the side end in four ones and upper end in the remained one model,with the diameter being 70,100,150,260 and 260 mm respectively;secondly,a standard k-ε turbulence model was applied to simulating the velocity field and concentration field inside the high efficiency particulate air filter device,so as to analyze the influence of the vortex position inside the device and the structure of the device on the disinfection effect and to determine the optimal structure of the device;finally,H2O2 with the concentration of 0.45,0.35 or 0.30 mol/L was selected as the disinectant to investigate the effect of the disinfectant concentration on the disinfection under the optimal device structure.Results Simulation showed that there were vortexes existed the cavity between the filter compression structure and the filter of the high efficiency particulate air filter device.The disinfection effect in case of the disinfection port at the side end was higher than that in case of the disinfection port at the upper end;the diameter of the disinfection port had influences on the disinfection effect,and high-concentration disinfectant was found in the device when the diameter was 100 mm.The optimal structure with the disinfection port at the side end and the diameter of 100 mm was determined for the high efficiency particulate air filter device.An increase in H2O2 concentration was beneficial to improve disinfection without corroding and damaging the device when the in-situ decontamination of the flow field-based biosafety high efficiency particulate air filter device was carried out.Conclusion The characteristics of the internal flow field of the flow field-based biosafety high efficiency particulate air filter device and the influencing factors of the in-situ disinfection effect are revealed,and theoretical references are provided for the optimal design of the device.[Chinese Medical Equipment Journal,2025,46(9):22-27]