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 explore the efficacy and safety of recombinant human anti-severe acute respiratory syn-drome coronavirus 2(anti-SARS-CoV-2)monoclonal antibody injection(F61 injection)in the treatment of patients with coronavirus disease 2019(COVID-19)combined with renal damage.Methods Patients with COVID-19 and renal damage who visited the PLA General Hospital from January to February 2023 were selected.Subjects were randomly divided into two groups.Control group was treated with conventional anti-COVID-19 therapy,while trial group was treated with conventional anti-COVID-19 therapy combined with F61 injection.A 15-day follow-up was conducted after drug administration.Clinical symptoms,laboratory tests,electrocardiogram,and chest CT of pa-tients were performed to analyze the efficacy and safety of F61 injection.Results Twelve subjects(7 in trial group and 5 in control group)were included in study.Neither group had any clinical progression or death cases.The ave-rage time for negative conversion of nucleic acid of SARS-CoV-2 in control group and trial group were 3.2 days and 1.57 days(P=0.046),respectively.The scores of COVID-19 related target symptom in the trial group on the 3rd and 5th day after medication were both lower than those of the control group(both P＜0.05).According to the clinical staging and World Health Organization 10-point graded disease progression scale,both groups of subjects improved but didn't show statistical differences(P＞0.05).For safety,trial group didn't present any infusion-re-lated adverse event.Subjects in both groups demonstrated varying degrees of elevated blood glucose,elevated urine glucose,elevated urobilinogen,positive urine casts,and cardiac arrhythmia,but the differences were not statistica-lly significant(all P＞0.05).Conclusion F61 injection has initially demonstrated safety and clinical benefit in trea-ting patients with COVID-19 combined with renal damage.As the domestically produced drug,it has good clinical accessibility and may provide more options for clinical practice.

At present， in vitro artificial liver support system has achieved a good therapeutic effect in the diseases such as liver failure due to various causes， non-function state before and after liver transplantation， and severe cholestasis. Non-bioartificial liver （NBAL） is widely used in clinical practice through various combinations of modes， mainly the plasma exchange mode for improving coagulation factors and albumin combined with other modes for enhancing the elimination of toxic substances in the body. Bioartificial liver （BAL）， based on the design concept of the synthesis and transformation of hepatocytes， has achieved rapid development in recent years. Patients with liver failure can almost obtain the normal physiological function of human liver after NBAL detoxification and BAL synthesis and transformation of active substances in the body. NBAL mode combined with BAL with a stable therapeutic effect according to the conditions of the patient is the direction of in vitro support treatment for patients with severe liver disease in the future.

[Objective] To explore the characteristics of lifestyle behaviors and mental health status among blood donors in Guangzhou, and to investigate the correlation between donation frequency and these factors. [Methods] A cross-sectional study was conducted among 13 042 whole blood donors from 17 street blood donation sites of Guangzhou Blood Center from May to August 2020. Descriptive analysis was used to describe the characteristics of lifestyle behaviors and mental health status among blood donors in Guangzhou. Ordinal multinomial logistic regression model was used to analyze the correlation between donation frequency and these factors. [Results] It was found that some of 13 042 blood donors had unhealthy habits, such as 6.8% (698/10 214，2 828 missing values) had severe tobacco dependence, 30.6% (3 997/13 042) had low exercise levels, 38.8%（5 056/13 042）had poor sleep quality, and 2.2% (271/12 159，883 missing values) had alcohol dependence. In addition, 2.8% (364/13 042) and 1.3% (172/13 042) of the donors may have moderate to severe depression and anxiety symptoms, respectively. The results of the ordinal multinomial logistic regression model showed that exercise level was significantly negatively correlated with the degree of depression and anxiety among blood donors. With the decrease in exercise level, the possibility of depression and anxiety among donors increased significantly. BMI, household income, education level, marital status, donation frequency, alcohol consumption and smoking had no significant correlation with the mental health status of donors. [Conclusion] Improving the exercise habits of blood donors may help enhance their mental health level. It is recommended that blood station staff strengthen the content of exercise when providing health education to blood donors to maintain a healthy lifestyle. It also suggests that there may be a certain degree of under-diagnosis of mental health problems in the process of health consultation before blood donation, and conducting more comprehensive and effective mental health assessments for blood donors is recommended.

Background::Thoracic aortic aneurysm (TAA) is a fatal cardiovascular disease, the pathogenesis of which has not yet been clarified. This study aimed to identify and validate the diagnostic markers of TAA to provide a strong theoretical basis for developing new methods to prevent and treat this disease.Methods::Gene expression profiles of the GSE9106, GSE26155, and GSE155468 datasets were acquired from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were identified using the "limma" package in R. Least absolute shrinkage and selection operator (LASSO), support vector machine-recursive feature elimination (SVM-RFE), random forest, and binary logistic regression analyses were used to screen the diagnostic marker genes. Single-sample gene set enrichment analysis (ssGSEA) was used to estimate immune cell infiltration in TAA.Results::A total of 16 DEGs were identified. The enrichment and functional correlation analyses showed that DEGs were mainly associated with inflammatory response pathways and collagen-related diseases. Collagen type I alpha 1 chain ( COL1A1) and synaptotagmin like 2 ( SYTL2) were identified as diagnostic marker genes with a high diagnostic value for TAA. The expression of COL1A1 and SYTL2 was considerably higher in TAA vascular wall tissues than in the corresponding normal tissues, and there were significant differences in the infiltration of immune cells between TAA and normal vascular wall tissues. Additionally, COL1A1 and SYTL2 expression were associated with the infiltration of immune cells in the vascular wall tissue. Single-cell analysis showed that COL1A1 in TAA was mainly derived from fibroblasts and SYTL2 mainly from cluster of differentiation (CD)8 + T cells. In addition, single-cell analysis indicated that fibroblasts and CD8 + T cells in TAA were significantly higher than those in normal arterial wall tissue. Conclusions::COL1A1 and SYTL2 may serve as diagnostic marker genes for TAA. The upregulation of SYTL2 and COL1A1 may be involved in the inflammatory infiltration of the vessel wall and poor extracellular matrix remodeling, promoting the progression of TAA.

Objective To observe the clinical efficacy of successive trigger needling combined with fire needling in the treatment of rheumatoid arthritis of cold-damp obstruction type.Methods A total of 72 patients with rheumatoid arthritis of cold-damp obstruction type were randomly divided into observation group and control group,36 cases in each group.The control group was treated with fire needling combined with ordinary acupuncture,and the observation group was treated with fire needling combined with filiform needle.The treatments were performed once every other day,3 times a week,2 weeks as a course of treatment,continuous treatment for 2 courses.After 4 weeks of treatment,the clinical efficacy of the two groups was evaluated.The changes of pain Visual Analogue Scale(VAS)score and Self-Rating Anxiety Scale(SAS)score before and after treatment,and the time of morning stiffness of the joints were observed in the two groups.The changes of the number of joint swelling and the number of joint tenderness were compared before and after treatment between the two groups.Results(1)After treatment,the time of morning stiffness of the joints of the two groups of patients was significantly improved(P＜0.05),and the observation group was significantly superior to the control group in improving morning stiffness of the joints,and the difference was statistically significant(P＜0.05).(2)After treatment,the number of swollen joints and the number of joint pressure and pain in the two groups were significantly improved(P＜0.05),and the observation group was significantly superior to the control group in improving swollen joints and joint pressure and pain,and the difference was statistically significant(P＜0.05).(3)After treatment,the VAS and SAS scores of patients in the two groups were significantly improved(P＜0.05),and the observation group was significantly superior to the control group in improving the VAS and SAS scores,and the difference was statistically significant(P＜0.05).(4)The total effective rate of the observation group was 91.66%(33/36),while that of the control group was 77.78%(28/36).The efficacy of the observation group was superior to that of the control group,and the difference was statistically significant(P＜0.05).Conclusion Successive trigger needling combined with fire needling treating rheumatoid arthritis of cold-damp obstruction type can significantly improve the clinical symptoms of patients,reduce their anxiety,and thus improve the quality of life of patients,with remarkable efficacy.

Objective To compare the oral cleansing effects of the microbubble toothbrush and the conventional pulsed oral irrigator to provide references for users.Methods Ninety identical 3D-printed resin tooth models were grouped and subjected to repeated experiments,which were divided randomly into five groups including a microbubble toothbrush high-speed gear(GN-H)group,a microbubble toothbrush medium-speed gear(GN-M)group,a microbubble low-speed gear(GN-L)group,a conventional pulsed oral irrigator high-speed gear(W-H)group and a conventional pulsed oral irrigator low-speed gear(W-L)group,with 18 teeth in each group.The cleansing effects of the microbubble toothbrush and the conventional pulsed oral irrigator were evaluated in terms of irrigating strength and abilities for eliminating plaque and debris.Results Both the two types of water flossers were provided with high irrigating strength and effectively reduced plaque and debris on tooth surfaces,and the GN-H,GN-M and GN-L groups behaved better significantly than the remained groups.The order of the five groups was GN-H group＞GN-M group＞W-H group＞GN-L group＞W-L group for irrigating strength,GN-H group＞GN-M group＞GN-L group＞W-H group＞W-L group for plaque removal,GN-H group＞GN-M group＞W-H group＞GN-L group＞W-L group for debris removal,with all the differences being statistically significant(P＜0.05).Conclusion Both the two types of water flossers remove plaque and debris effectively,while the microbubble toothbrush gains advantages over the conventional pulsed oral irrigator.[Chinese Medical Equipment Journal,2024,45(9):67-72]

Objective To investigate the effect and mechanism of andrographolide(AG)on lipopolysaccharide(LPS)-induced ferroptosis in renal tubular epithelial cells(HK-2 cells).Methods HK-2 cells were treated with LPS to simulate the in vitro HK-2 injury model of sepsis.The cells were further treated with AG of 5,10,20,40 μmol/L and randomly divided into control group,LPS group,LPS+dimethyl sulfoxide group(DMSO group),and AG group.Cell viability was detected by the CCK-8 method,and the optimal concentrations of LPS and AG were screened.Cell morphological change,the levels of kidney injury markers,including neutrophil gelatinase-associated lipocalin(NGAL),kidney injury molecule-1(KIM-1),malondialdehyde(MDA),glutathione(GSH)and reactive oxygen species(ROS),as well as the expression levels of ferroptosis regulatory proteins such as solute carrier family 7 member 11(SLC7A11),glutathione peroxidase 4(GPX4)and ferritin in each group were compared,and the pro-tective effect of AG treatment on the cells was evaluated.Results Compared with the control group,the cell viabi-lity and GSH content decreased significantly in HK-2 cells treated with 10 μg/mL LPS;cell shrinkage and adhesion ability were poor;the contents of oxidative products MDA and ROS,as well as the levels of kidney injury markers NGAL and KIM-1 increased significantly,while expression levels of SLC7A11 and GPX4 protein decreased;ferritin expression level increased;differences were all statistically significant(all P＜0.05).Compared with LPS group,the cell viability,GSH content,as well as protein expression levels of SLC7A11 and GPX4 increased significantly after AG intervention,while ferritin expression level decreased,differences were all significant(all P＜0.05).MDA content,ROS fluorescence intensity,and the levels of kidney injury markers NGAL and KIM-1 decreased sig-nificantly,difference were all significant(all P＜0.05).Conclusion AG has a protective effect on LPS-induced HK-2 cell injury,possibly by activating SLC7A11/GPX4 pathway,reducing oxidative stress,up-regulating antioxi-dant enzyme activity,and alleviating ferroptosis.

Objective To investigate the distribution and antimicrobial resistance profiles of the common pathogens isolated from urine from 2015 to 2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods The bacterial strains were isolated from urine and identified routinely in 51 hospitals across China in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Antimicrobial susceptibility was determined by Kirby-Bauer method,automatic microbiological analysis system and E-test according to the unified protocol.Results A total of 261 893 nonduplicate strains were isolated from urine specimen from 2015 to 2021,of which gram-positive bacteria accounted for 23.8％(62 219/261 893),and gram-negative bacteria 76.2％(199 674/261 893).The most common species were E.coli(46.7％),E.faecium(10.4％),K.pneumoniae(9.8％),E.faecalis(8.7％),P.mirabilis(3.5％),P.aeruginosa(3.4％),SS.agalactiae(2.6％),and E.cloacae(2.1％).The strains were more frequently isolated from inpatients versus outpatients and emergency patients,from females versus males,and from adults versus children.The prevalence of ESBLs-producing strains in E.coli,K.pneumoniae and P.mirabilis was 53.2％,52.8％and 37.0％,respectively.The prevalence of carbapenem-resistant strains in E.coli,K.pneumoniae,P.aeruginosa and A.baumannii was 1.7％,18.5％,16.4％,and 40.3％,respectively.Lower than 10％of the E.faecalis isolates were resistant to ampicillin,nitrofurantoin,linezolid,vancomycin,teicoplanin and fosfomycin.More than 90％of the E.faecium isolates were ressitant to ampicillin,levofloxacin and erythromycin.The percentage of strains resistant to vancomycin,linezolid or teicoplanin was＜2％.The E.coli,K.pneumoniae,P.aeruginosa and A.baumannii strains isolated from ICU inpatients showed significantly higher resistance rates than the corresponding strains isolated from outpatients and non-ICU inpatients.Conclusions E.coli,Enterococcus and K.pneumoniae are the most common pathogens in urinary tract infection.The bacterial species and antimicrobial resistance of urinary isolates vary with different populations.More attention should be paid to antimicrobial resistance surveillance and reduce the irrational use of antimicrobial agents.

Objective To understand the distribution and changing resistance profiles of clinical isolates of Enterococcus in hospitals across China from 2015 to 2021.Methods Antimicrobial susceptibility testing was conducted for the clinical isolates of Enterococcus according to the unified protocol of CHINET program by automated systems,Kirby-Bauer method,or E-test strip.The results were interpreted according to the Clinical & Laboratory Standards Institute(CLSI)breakpoints in 2021.WHONET 5.6 software was used for statistical analysis.Results A total of 124 565 strains of Enterococcus were isolated during the 7-year period,mainly including Enterococcus faecalis(50.7％)and Enterococcus faecalis(41.5％).The strains were mainly isolated from urinary tract specimens(46.9％±2.6％),and primarily from the patients in the department of internal medicine,surgery and ICU.E.faecium and E.faecalis strains showed low level resistance rate to vancomycin,teicoplanin and linezolid(≤3.6％).The prevalence of vancomycin-resistant E.faecalis and E.faecium was 0.1％and 1.3％,respectively.The prevalence of linezolid-resistant E.faecalis increased from 0.7％in 2015 to 3.4％in 2021,while the prevalence of linezolid-resistant E.faecium was 0.3％.Conclusions The clinical isolates of Enterococcus were still highly susceptible to vancomycin,teicoplanin,and linezolid,evidenced by a low resistance rate.However,the prevalence of linezolid-resistant E.faecalis was increasing during the 7-year period.It is necessary to strengthen antimicrobial resistance surveillance to effectively identify the emergence of antibiotic-resistant bacteria and curb the spread of resistant pathogens.