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 mediating role of activities of daily living (ADL) in pain and depressive symptoms in the elderly in China. Methods Utilizing the data from 2020 China Health and Retirement Longitudinal Study, 4403 Chinese elderly individuals aged ≥ 60 years old were selected as the research subjects. Depression Scale (CES-D 10) of the Center for Epidemiological Survey and ADL scale were used in the study. The PROCESS4.1 macro was used to test the mediating effect of daily living activities between pain and depressive symptoms, and the Bootstrap method was applied for verification of the mediating variables. Results A total of 2368 cases of depressive symptoms were detected in the elderly in China, with a detection rate of 53.78%. Pain was positively correlated with depressive symptoms (r=0.27, P<0.01), and activities of daily living were negatively correlated with pain and depressive symptoms (r=-0.27, -0.337, P<0.01). The results showed that the total effect value of pain on depressive symptoms was 0.33, the direct effect value was 0.24, and the mediating effect value of daily living activities was 0.09, accounting for 27.27%. Conclusion Pain and activities of daily living are important factors influencing depressive symptoms in the elderly, and activities of daily living play a partial mediating role in the relationship between pain and depressive symptoms in the elderly.

Iron is indispensable for the viablility of nearly all living organisms, and it is imperative for cells, tissues, and organisms to acquire this essential metal sufficiently and maintain its metabolic stability for survival. Disruption of iron homeostasis can lead to the development of various diseases. There is a robust connection between iron metabolism and infection, immunity, inflammation, and aging, suggesting that disorders in iron metabolism may contribute to the pathogenesis of arthritis. Numerous studies have focused on the significant role of iron metabolism in the development of arthritis and its potential for targeted drug therapy. Targeting iron metabolism offers a promising approach for individualized treatment of arthritis. Therefore, this review aimed to investigate the mechanisms by which the body maintains iron metabolism and the impacts of iron and iron metabolism disorders on arthritis. Furthermore, this review aimed to identify potential therapeutic targets and active substances related to iron metabolism, which could provide promising research directions in this field.

Background::Carotid intima-media thickness (IMT) and diameter, stiffness, and wave reflections, are independent and important clinical biomarkers and risk predictors for cardiovascular diseases. The purpose of the present study was to establish nationwide reference values of carotid properties for healthy Chinese adults and to explore potential clinical determinants.Methods::A total of 3053 healthy Han Chinese adults (1922 women) aged 18-79 years were enrolled at 28 collaborating tertiary centers throughout China between April 2021 and July 2022. The real-time tracking of common carotid artery walls was achieved by the radio frequency (RF) ultrasound system. The IMT, diameter, compliance coefficient, β stiffness, local pulse wave velocity (PWV), local systolic blood pressure, augmented pressure (AP), and augmentation index (AIx) were then automatically measured and reported. Data were stratified by age groups and sex. The relationships between age and carotid property parameters were analyzed by Jonckheere-Terpstra test and simple linear regressions. The major clinical determinants of carotid properties were identified by Pearson’s correlation, multiple linear regression, and analyses of covariance.Results::All the parameters of carotid properties demonstrated significantly age-related trajectories. Women showed thinner IMT, smaller carotid diameter, larger AP, and AIx than men. The β stiffness and PWV were significantly higher in men than women before forties, but the differences reversed after that. The increase rate of carotid IMT (5.5 μm/year in women and 5.8 μm/year in men) and diameter (0.03 mm/year in both men and women) were similar between men and women. For the stiffness and wave reflections, women showed significantly larger age-related variations than men as demonstrated by steeper regression slopes (all P for age by sex interaction <0.05). The blood pressures, body mass index (BMI), and triglyceride levels were identified as major clinical determinants of carotid properties with adjustment of age and sex. Conclusions::The age- and sex-specific reference values of carotid properties measured by RF ultrasound for healthy Chinese adults were established. The blood pressures, BMI, and triglyceride levels should be considered for clinical application of corresponding reference values.

Aim To analyze serum exosome sequencing data from patients with coronary heart disease(CHD)and normal subjects by using bioinformatics-related methods to construct a competitive endogenous ln-cRNA-miRNA-mRNA(ceRNA)regulatory network,to mine the predicted potential Chinese medicines,and to perform preliminary validation of the biological processes and core Chinese medicines involved in the ceRNA network.Methods We used exoRbase data-base to obtain the expression matrix of differential genes,combined with the raw letter method to con-struct the ceRNA network,and performed GO analysis and KEGG analysis on the differential mRNAs in the network,and used COREMINE database to predict the biological processes and core target genes involved in the ceRNA network,and to screen the herbal medi-cines with potential therapeutic effects;AVECs oxida-tive damage cell model was constructed in vitro,and the cytoskeleton,tube-forming function,cell prolifera-tion,LDH leakage rate,ROS level and p-AKT,AKT,p-PI3K and AKT protein expression were examined to verify the action pathways and targets of the core Chi-nese medicine Salvia miltiorrhiza for the treatment of coronary heart disease.Results Compared with nor-mal subjects,395 mRNAs,80 miRNAs,60 lncRNA differential genes,and 80 miRNAs were predicted in serum exosomes of coronary heart disease,and the constructed ceRNA sub-network,mainly consisted of 21 lncRNAs,80 miRNAs,and 82 mRNAs;AKT1,VEGFA,IL1B and other genes in the network.The abnormally expressed mRNAs were involved in biologi-cal processes such as oxidative stress and signaling pathways such as PI3 K/Akt,and Dan Shen,Chuanx-iong and Panax notoginseng were most closely related to exosome-mediated biological processes and core genes in coronary heart disease.The active ingredients of tanshinone ⅡA,the core Chinese medicine,could pro-mote vascular endothelial cell proliferation,tube for-mation,skeleton formation and repair,reduce LDH leakage rate and ROS level,and promote the expres-sion of p-AKT and p-PI3K protein.Conclusion There is a complex ceRNA regulatory network trans-duction in coronary artery disease serum exosomes,and traditional Chinese medicine can be used to treat CHD through multi-target intervention,and Dan Shen,Chuanxiong and Panax notoginseng are expected to be candidate sources of traditional Chinese medicine,a-mong which the active ingredient of Dan Shen,tanshi-none ⅡA,activates PI3 K/Akt signaling pathway to play a protective role against oxidative stress-injured cells,and treats CHD.

Aim To investigate the mechanism of icar-itin(ICT)on D-galactose(D-gal)-induced TM4 ser-toli cell junctional function damage in vitro.Methods TM4 cells were divided into the normal control group and D-gal treatment group with different concentra-tions.The expression changes of TM 4 cell junction function-related proteins(ZO-1,Occludin,β-catenin and Cx43)and ERα/FAK signaling pathway-related proteins(ERα,FAK and pY397-FAK)were detected by Western blot.The concentration of ICT was screened by MTT method.TM4 cells were divided into normal control group,D-gal treatment group,and D-gal treatment+different concentrations of ICT group.The expression levels of the above proteins were detected by Western blot.Molecular docking was used to study the interaction between ERα and ICT,meanwhile predict the affinity between them.Finally,TM4 cells were di-vided into normal control group,D-gal treatment group,ERα inhibitor group,D-gal+ICT group,and ERα inhibitor+ICT group.The expression levels of the above proteins were detected by Western blot.Re-sults Compared with the normal control group,the ex-pression of junctional function-related proteins(ZO-1,Occludin,β-catenin and Cx43)and ERα/FAK signa-ling pathway-related proteins(ERα,FAK and pY397-FAK)were significantly down-regulated.After treat-ment with ICT,the expression of above proteins were significantly up-regulated.The docking results of ERα and ICT molecules revealed the formation of two hydro-gen bonds between Asp351 amino acid residue of ERα and ICT,with bond distances measuring 3.4? and 2.4?.Additionally,the docking binding energy be-tween them was found to be lower than-7 kcal·mol-1.After TM4 cells were treated with ERα inhibi-tor,the expression of above proteins and ERα/FAK signaling pathway-related proteins were significantly down-regulated,while the expression levels of the a-bove proteins did not change significantly after being given ICT protected group.Conclusions D-gal can cause damage to the junctional function of TM4 cells,and ICT can improve this damage,which may be related to the up-regulation of ERα/FAK signaling pathway.

Aim To explore the core target,key com-ponents and mechanism of Tibetan medicine Rhodiola crenulata in improving cerebral microcirculation based on literature research,network pharmacology,molecu-lar docking and experimental verification.Methods The chemical components of Rhodiola were collected through literature and database,and the potential tar-gets of Rhodiola crenulata were predicted by reverse pharmacophore matching.The related targets of cere-bral microcirculation disorder were obtained and targets were mapping with Rhodiola crenulata.PPI network was constructed and the core targets were screened.The regulatory network of"herb-component-target-dis-ease"was constructed and key components were screened.GO and KEGG enrichment analysis were conducted,and a"Core target-Pathway-Biological Process"network was constructed.Finally,molecular docking validation was carried out,and RT-qPCR and Western blot were used for animal experiments to fur-ther confirm the results of network pharmacology analy-sis.Results A total of 76 active components of Rhodiola crenulata were obtained and corresponding to 285 targets.Altogether 1074 related targets related to cerebral microcirculation disorder were obtained.A-mong them,there were 97 common targets and the main core targets were 6.The key components were 6.The results of molecular docking showed that the bind-ing activity of three key components to the core target was greater than that of the core target protein and its original ligand.The result of RT-qPCR and Western blot demonstrated that Tibetan medicine Rhodiola cre-nulata could significantly reduce the expression of core target CASP3 and AKT1(P＜0.01).Conclusions Tibetan medicine Rhodiola crenulata can improve the cerebral microcirculation disorder through multi compo-nents,multi targets and multi pathways.This study provides an experimental basis for clinical application of Tibetan medicine Rhodiola crenulata to treat cerebral microcirculation disorder.

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in tertiary hospitals in major regions of China in 2022.Methods Clinical isolates from 58 hospitals in China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2022 Clinical &Laboratory Standards Institute(CLSI)breakpoints.Results A total of 318 013 clinical isolates were collected from January 1,2022 to December 31,2022,of which 29.5％were gram-positive and 70.5％were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species(excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi)was 28.3％,76.7％and 77.9％,respectively.Overall,94.0％of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 90.8％of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis showed significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 94.2％in the isolates from children and 95.7％in the isolates from adults.The resistance rate to carbapenems was lower than 13.1％in most Enterobacterales species except for Klebsiella,21.7％-23.1％of which were resistant to carbapenems.Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.1％to 13.3％.The prevalence of meropenem-resistant strains decreased from 23.5％in 2019 to 18.0％in 2022 in Pseudomonas aeruginosa,and decreased from 79.0％in 2019 to 72.5％in 2022 in Acinetobacter baumannii.Conclusions The resistance of clinical isolates to the commonly used antimicrobial agents is still increasing in tertiary hospitals.However,the prevalence of important carbapenem-resistant organisms such as carbapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a downward trend in recent years.This finding suggests that the strategy of combining antimicrobial resistance surveillance with multidisciplinary concerted action works well in curbing the spread of resistant bacteria.

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.