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.

ObjectivePhotoacoustic pump-probe imaging can effectively eliminate the interference of blood background signal in traditional photoacoustic imaging, and realize the imaging of weak phosphorescence molecules and their triplet lifetimes in deep tissues. However, background differential noise in photoacoustic pump-probe imaging often leads to large fitting results of phosphorescent molecule concentration and triplet lifetime. Therefore, this paper proposes a novel triplet lifetime fitting method for photoacoustic pump-probe imaging. By extracting the phase of the triplet differential signal and the background noise, the fitting bias caused by the background noise can be effectively corrected. MethodsThe advantages and feasibility of the proposed algorithm are verified by numerical simulation, phantom and in vivo experiments, respectively. ResultsIn the numerical simulation, under the condition of noise intensity being 10% of the signal amplitude, the new method can optimize the fitting deviation from 48.5% to about 5%, and has a higher exclusion coefficient (0.88>0.79), which greatly improves the fitting accuracy. The high specificity imaging ability of photoacoustic pump imaging for phosphorescent molecules has been demonstrated by phantom experiments. In vivo experiments have verified the feasibility of the new fitting method proposed in this paper for fitting phosphoometric lifetime to monitor oxygen partial pressure content during photodynamic therapy of tumors in nude mice. ConclusionThis work will play an important role in promoting the application of photoacoustic pump-probe imaging in biomedicine.

BACKGROUND:We have successfully established an animal model of small ear pig in southern Yunnan province with internal tension relieving technique combined with autologous Achilles tendon for anterior cruciate ligament reconstruction,and verified the stability and reliability of the model.However,whether internal tension relieving technique can promote the ligamentalization process of autologous Achilles tendon graft has not been studied. OBJECTIVE:To investigate the differences in the process of ligamentalization between conventional reconstruction and internal reduction reconstruction of the anterior cruciate ligament by gross view,histology and electron microscopy. METHODS:Thirty adult female small ear pigs in southern Yunnan province were selected.Anterior cruciate ligament reconstruction was performed on the left knee joint with the ipsilateral knee Achilles tendon(n=30 in the normal group),and anterior cruciate ligament reconstruction was performed on the right knee joint with the ipsilateral knee Achilles tendon combined with the internal relaxation and enhancement system(n=30 in the relaxation group).The autogenous right forelimb was used as the control group;the anterior cruciate ligament was exposed but not severed or surgically treated.At 12,24,and 48 weeks after surgery,10 animals were sacrificed,respectively.The left and right knee joint specimens were taken for gross morphological observation to evaluate the graft morphology.MAS score was used to evaluate the excellent and good rate of the ligament at each time point.Hematoxylin-eosin staining was used to evaluate the degree of ligament graft vascularization.Collagen fibers and nuclear morphology were observed,and nuclear morphology was scored.Ultrastructural remodeling was evaluated by scanning electron microscopy and transmission electron microscopy. RESULTS AND CONCLUSION:(1)The ligament healing shape of the relaxation group was better at various time points after surgery,and the excellent and good rate of MAS score was higher(P<0.05).Moreover,the relaxation group could obtain higher ligament vascularization score(P<0.05).(2)The arrangement of collagen bundles and fiber bundles in the two groups gradually tended to be orderly,and the transverse fiber connections between collagen gradually increased and thickened,suggesting that the strength and shape degree of the grafts were gradually improved,but the ligament remodeling in the relaxation group was always faster than that in the normal group at various time points after surgery.(3)The diameter,distribution density,and arrangement degree of collagen fibers in the relaxation group were better than those in the normal group at all time points,especially in the comparison of collagen fiber diameter between and within the relaxation group(P<0.05).

Objective:To investigate the application of the parameters of multimodal ultrasound elastography in differential diagnosis for thyroid nodules of patients with diffuse thyroid lesions.Methods:A total of 103 patients with diffuse thyroid lesions who underwent treatment at Affiliated Baoji Hospital of Xi′an Medical University from January 2023 to January 2024 were retrospectively selected,whose thyroid nodules were confirmed by fine needle aspiration biopsy or surgical pathology.They were grouped according to the benign or malignant nodules.56 patients with benign nodules were included in the benign nodule group,while the other 47 patients were included in the malignant nodule group.All patients were examined by conventional ultrasound and multimodal ultrasound elastography,and the relevant parameters were recorded to compare the differences between the two groups.The value of each indicator in diagnosing benign and malignant thyroid nodules was investigated.Results:There were no statistically significant differences between the benign and malignant nodule groups in terms of gender,length diameter of nodule,nodule location,functional abnormalities of thyroid,exposure history of radiation,and the presence of acoustic halos(P＞0.05),the age of patients in the malignant nodule group was lower than that of the benign nodule group(t=-3.121,P＜0.05),and the percentage of nodules with blood flow(14.89%),the percentage of aspect ratio＜1(74.47%),and the percentage of nodules with clear boundary(27.66%)in the malignant nodule group were all lower than those of the benign nodule group,with statistically significant differences(x2=25.634,5.112,12.465,P＜0.05).The ratio of lymphatic metastasis(27.66%)and that of calcification(65.96%)in the malignant nodule group were lower than those in the benign nodule group,and the differences were all statistically significant(x2=11.917,9.350,P＜0.05).The ratios of centripetal enhancement(76.60%),inhomogeneous enhancement(68.09%),low/equal enhancement(87.23%),early obvious discharge(63.83%),unclear boundary after enhancement(91.49%),and fast discharge(59.57%)in the malignant nodule group were higher than that of the benign nodule group,and the differences were statistically significant(x2=33.409,26.695,9.079,12.853,17.798,12.649,P＜0.05),respectively.The intensity and time to peak of the malignant nodule group were respectively lower and long than these of the benign nodule group,and the differences were statistically significant(t=-12.381,4.958,P＜0.05).However,the mean passage time of the two groups was not statistically significant(P＞0.05).The maximum value,minimum value and mean value of Young's modulus,the maximum value of vertical section,mean value of vertical section,maximum value of cross section,mean value of cross section in the malignant nodule group were all higher than those in the benign nodule group,and the differences were statistically significant(t=13.997,9.100,12.191,7.616,6.310,4.679,5.355,P＜0.05).The result of receiver operating characteristic(ROC)curve analysis indicated that both ultrasonography parameters and shear wave elastography(SWE)parameters had higher diagnostic value for the benign and malignant nature of thyroid nodules in patients.The area under curve(AUC)values of intensity to peak,time to peak,and the maximum value,minimum value and mean value of Young's modulus,and the maximum value of vertical section,mean value of vertical section,maximum value of cross section,mean value of cross section were respectively 0.976,0.759,0.974,0.837,0.989,0.872,0.805,0.732 and 0.749.Conclusion:Multimodal ultrasound elastography parameters has significant application value in differential diagnosis for thyroid nodules in patients with diffuse thyroid lesions.In these parameters,the diagnostic AUC values of intensity to peak,time to peak,and the maximum value and mean value of Young's modulus are higher for malignant thyroid nodules of patients,which have higher diagnostic efficiency.It can effectively help clinical doctor to accurately identify the benign and malignant nodules for patients with diffuse thyroid lesions.

With the rapid development of generative artificial intelligence(GAI)technologies,their widespread application in academic research and writing is continuously expanding the boundaries of sci-entific inquiry.However,this trend has also raised a series of ethical and regulatory challenges,inclu-ding issues related to authorship,content authenticity,citation accuracy,and accountability.In light of the growing involvement of AI in generating academic content,establishing an open,controllable,and trustworthy ethical governance framework has become a key task for safeguarding research integrity and maintaining trust within the academic community.This expert consensus outlines ethical requirements across key stages of AI-assisted academic writing-including topic selection,data management,citation practices,and authorship attribution.It aims to clarify the boundaries and ethical obligations surrounding AI use in academic writing,ensuring that technological tools enhance efficiency without compromising in-tegrity.The goal is to provide guidance and institutional support for building a responsible and sustainable research ecosystem.

Objective To summarize the changing prevalence of carbapenem resistance in Enterobacterales based on the data of CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021 for improving antimicrobial treatment in clinical practice.Methods Antimicrobial susceptibility testing was performed using a commercial automated susceptibility testing system according to the unified CHINET protocol.The results were interpreted according to the breakpoints of the Clinical & Laboratory Standards Institute(CLSI)M100 31st ed in 2021.Results Over the seven-year period(2015-2021),the overall prevalence of carbapenem-resistant Enterobacterales(CRE)was 9.43％(62 342/661 235).The prevalence of CRE strains in Klebsiella pneumoniae,Citrobacter freundii,and Enterobacter cloacae was 22.38％,9.73％,and 8.47％,respectively.The prevalence of CRE strains in Escherichia coli was 1.99％.A few CRE strains were also identified in Salmonella and Shigella.The CRE strains were mainly isolated from respiratory specimens(44.23±2.80)％,followed by blood(20.88±3.40)％and urine(18.40±3.45)％.Intensive care units(ICUs)were the major source of the CRE strains(27.43±5.20)％.CRE strains were resistant to all the β-lactam antibiotics tested and most non-β-lactam antimicrobial agents.The CRE strains were relatively susceptible to tigecycline and polymyxins with low resistance rates.Conclusions The prevalence of CRE strains was increasing from 2015 to 2021.CRE strains were highly resistant to most of the antibacterial drugs used in clinical practice.Clinicians should prescribe antimicrobial agents rationally.Hospitals should strengthen antibiotic stewardship in key clinical settings such as ICUs,and take effective infection control measures to curb CRE outbreak and epidemic in hospitals.

Objective To characterize the changing species distribution and antibiotic resistance profiles of respiratory isolates in hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Methods Commercial automated antimicrobial susceptibility testing systems and disk diffusion method were used to test the susceptibility of respiratory bacterial isolates to antimicrobial agents following the standardized technical protocol established by the CHINET program.Results A total of 589 746 respiratory isolates were collected from 2015 to 2021.Overall,82.6％of the isolates were Gram-negative bacteria and 17.4％were Gram-positive bacteria.The bacterial isolates from outpatients and inpatients accounted for(6.0±0.9)％and(94.0±0.1)％,respectively.The top microorganisms were Klebsiella spp.,Acinetobacter spp.,Pseudomonas aeruginosa,Staphylococcus aureus,Haemophilus spp.,Stenotrophomonas maltophilia,Escherichia coli,and Streptococcus pneumoniae.Each microorganism was isolated from significantly more males than from females(P＜0.05).The overall prevalence of methicillin-resistant S.aureus(MRSA)was 39.9％.The prevalence of penicillin-resistant S.pneumoniae was 1.4％.The prevalence of extended-spectrum β-lactamase(ESBL)-producing E.coli and K.pneumoniae was 67.8％and 41.3％,respectively.The overall prevalence of carbapenem-resistant E.coli,K.pneumoniae,Enterobacter cloacae,Pseudomonas aeruginosa,and Acinetobacter baumannii was 3.7％,20.8％,9.4％,29.8％,and 73.3％,respectively.The prevalence of β-lactamase was 96.1％in Moraxella catarrhalis and 60.0％in Haemophilus influenzae.The H.influenzae isolates from children(＜18 years)showed significantly higher resistance rates to β-lactam antibiotics than the isolates from adults(P＜0.05).Conclusions Gram-negative bacteria are still predominant in respiratory isolates associated with serious antibiotic resistance.Antimicrobial resistance surveillance should be strengthened in clinical practice to support accurate etiological diagnosis and appropriate antimicrobial therapy based on antimicrobial susceptibility testing results.

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 value of serum P-selectin,Interleukin-18(IL-18),and Homocysteine(Hcy)levels in predicting the adverse outcomes of interventional therapy in elderly patients with deep vein thrombosis(DVT)in the lower extremities.Methods:A total of 165 elderly patients with DVT from January 2020 to August 2023 were se-lected.All patients underwent transcatheter intervention thrombolysis therapy.Patients were divided into good outcome group and poor outcome group according to the clinical treatment outcome.Serum P-selectin,IL-18,and Hcy levels were compared between the two groups.The correlation between serum P-selectin,IL-18,and Hcy levels and disease indicators,as well as the outcomes of interventional therapy was analyzed.The predictive value of serum P-selectin,IL-18,and Hcy levels for the outcomes of interventional therapy was evaluated.Results:The total effective rate of catheter-based interventional thrombolysis in 165 patients was 81.82%(135/165).The patients with good outcomes were included in the good outcome group,and the patients with poor outcomes were included in the poor outcome group.The difference in circumference between the affected side and the healthy side of the thigh and the difference in circumference between the affected side and the healthy side of the calf in the poor outcome group were greater than those in the good outcome group(P<0.05).The levels of serum P-selectin,IL-18,and Hcy in the poor outcome group were higher than those in the good outcome group(P<0.05).The levels of serum P-selectin,IL-18,and Hcy were posi-tively correlated with the difference in circumference between the affected and healthy thighs and the difference in cir-cumference between the affected and healthy calves,and negatively correlated with the outcome of interventional therapy(P<0.05).Before and after correcting other factors,serum P-selectin,IL-18,and Hcy were all independent risk factors for the outcome of interventional therapy in elderly patients with DVT(P<0.05).The area under the curve(AUC)of serum P-selectin,IL-18,and Hcy for predicting the outcome of interventional therapy for elderly DVT was 0.789(95%CI:0.718-0.848),0.812(95%CI:0.744-0.868),and 0.792(95%CI:0.722-0.851),respectively.The cutoff values were 44.21 ng/mL,185.73 ng/L,and 23.60 μmol/L,with sensitivities of 70.00%,70.00%,and 80.00%,and specificities of 82.22%,82.96%,and 68.15%,respectively.The AUC of the combined prediction of the outcomes of interventional therapy for elderly DVT was 0.935(95%CI:0.886-0.967),with a cutoff value of 44.08 ng/mL,185.16 ng/L,and 23.37 μmol/L for the three variables,with a sensitivity of 86.67%and a specificity of 88.15%.This was significantly better than the individual prediction values of the three variables(Z=5.817,4.753,5.206,all P<0.001).Conclusion:Serum P-selectin,IL-18,and Hcy are significantly correlated with disease indicators and interventional treatment outcomes in el-derly patients with DVT,and can effectively predict the outcome of interventional treatment,with a high combined pre-dictive value.

Objective To investigate the distribution and antimicrobial resistance profiles of common pathogens isolated from cerebrospinal fluid(CSF)in CHINET program from 2015 to 2021.Methods The bacterial strains isolated from CSF were identified in accordance with clinical microbiology practice standards.Antimicrobial susceptibility test was conducted using Kirby-Bauer method and automated systems per the unified CHINET protocol.Results A total of 14 014 bacterial strains were isolated from CSF samples from 2015 to 2021,including the strains isolated from inpatients(95.3％)and from outpatient and emergency care patients(4.7％).Overall,19.6％of the isolates were from children and 80.4％were from adults.Gram-positive and Gram-negative bacteria accounted for 68.0％and 32.0％,respectively.Coagulase negative Staphylococcus accounted for 73.0％of the total Gram-positive bacterial isolates.The prevalence of MRSA was 38.2％in children and 45.6％in adults.The prevalence of MRCNS was 67.6％in adults and 69.5％in children.A small number of vancomycin-resistant Enterococcus faecium(2.2％)and linezolid-resistant Enterococcus faecalis(3.1％)were isolated from adult patients.The resistance rates of Escherichia coli and Klebsiella pneumoniae to ceftriaxone were 52.2％and 76.4％in children,70.5％and 63.5％in adults.The prevalence of carbapenem-resistant E.coli and K.pneumoniae(CRKP)was 1.3％and 47.7％in children,6.4％and 47.9％in adults.The prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)and Pseudomonas aeruginosa(CRPA)was 74.0％and 37.1％in children,81.7％and 39.9％in adults.Conclusions The data derived from antimicrobial resistance surveillance are crucial for clinicians to make evidence-based decisions regarding antibiotic therapy.Attention should be paid to the Gram-negative bacteria,especially CRKP and CRAB in central nervous system(CNS)infections.Ongoing antimicrobial resistance surveillance is helpful for optimizing antibiotic use in CNS infections.