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.

The health of women and children serves as the cornerstone of comprehensive public health and represents a crucial barometer for measuring social progress and civilization. It directly impacts family well-being and social harmony. As a national-level guidance center for complex disease diagnosis and treatment, Beijing's critical maternal care center, and the designated consultation hospital for pregnancy complicated by rheumatic immune and endocrine disorders, Peking Union Medical College Hospital bears significant responsibilities in managing complex medical cases and implementing counterpart assistance programs. Confronted with diverse and complicated maternal sources, particularly emergency cases lacking standardized prenatal care, the hospital has established a multi-tiered, whole-process, and comprehensive maternal-infant safety management system. Through implementing high-risk maternal management protocols, optimizing critical care procedures, promoting informatization development, and enhancing multidisciplinary collaboration, Peking Union Medical College Hospital has substantially improved the efficiency of critical maternal care and maternal-infant safety assurance. This paper systematically summarizes the institutional development experience in maternal management and explores potential optimization approaches, aiming to provide valuable references for enhancing maternal-infant safety management systems in domestic healthcare institutions.

Objective To develop a deep learning model based on fundus retinal images to improve the detection rate of mild cognitive impairment(MCI)in patients with coronary heart disease,achieve early intervention and improve prognosis.Methods The study was a single-center cross-sectional study that retrospectively included patients diagnosed with coronary heart disease(CHD)by coronary angiography(≥50％ stenosis of at least one coronary vessel)from Beijing Anzhen Hospital between November 2021 and December 2022.The whole data set was randomly divided into the training set and the testing set according to the ratio of 8∶2 for model development.After that,the patient data of the same center from January 2023 to April 2023 were included in the time verification method to verify the model.The diagnostic criteria for MCI were MMSE＜27 or MoCA＜26.Four kinds of convolutional neural network(CNN)architectures were used to train fundus images,and a comprehensive vision model of MCI detection was established through model integration.The area under the curve(AUC),sensitivity and specificity of the receiver operating curve(ROC)were used to evaluate the performance of the AI model.Results We collected 5 880 eligible fundus images from 3 368 CHD patients.Based on the results of the MMSE scale,the algorithm was labeled,including 2 898 males and 527 MCI patients.The AUC of the deep learning model in the test group is 0.733(95％CI 0.688-0.778),and the sensitivity of the algorithm in the test group is 0.577(95％CI 0.528-0.625)by using the operating point with the maximum sum of sensitivity and specificity.With a specificity of 0.758(95％CI 0.714-0.802),corresponding to a validated AUC of 0.710(95％CI 0.601-0.818).Based on the results of the MoCA scale,the algorithm labels 2 437 males and 1 626 MCI patients.The AUC of the deep learning model in the test group was 0.702(95％CI 0.671-0.733).The operating point with the maximum sum of sensitivity and specificity was selected,and the sensitivity of the algorithm was 0.749(95％CI 0.719-0.778)and the specificity was 0.561(95％CI 0.527-0.595),corresponding to the AUC value of the verification group was 0.674(95％CI 0.622-0.726).Conclusions The deep learning algorithm model based on fundus images has good diagnostic performance,and may be used as a new non-invasive,convenient and rapid screening method for MCI in CHD population.

Mesenchymal stem cells(MSCs)play a crucial role in tissue repair and regeneration,and the extracellular vesicle(EV)released by them holds great promise for applications in clinical biomarkers,vaccines,and drug delivery.However,MSCs-derived EV(MSCs-EV)face challenges such as low pro-duction yield,poor retention,and targeted delivery issues.There-fore,engineering MSCs-EV to enhance their performance and en-able visual research has become a hot topic.Curcumin(CUR),an active component in traditional chinese medicine,exhibits pharmacological effects but has limited bioavailability.Using MSCs-EV as a carrier for CUR delivery can address its solubility and bioavailability challenges.This article reviews the drug loading methods,engineering strategies of MSCs-EV,and their important applications in the delivery and treatment of CUR for cartilage injury diseases.It provides a basis for the clinical ap-plication of engineered MSCs-EV in CUR delivery for cartilage repair,offering potential solutions to the challenges in cartilage tissue repair.

Aim To explore the mechanism of Gano-derma lucidum polysaccharides(GLPS)promoting my-elin repair and regeneration in mice with chronic demy-elination induced by cuprizone(CPZ).Methods A total of 40 C57BL/6 mice were randomly divided into four groups:Normal+NS,Normal+GLPS,CPZ+NS and CPZ+GLPS.A chronic demyelination model was established using 0.2％CPZ.Open field and elevated plus maze tests were performed to observe the behavior-al changes in the mice.Immunofluorescence staining and Western blot were used to detect changes in myelin basic protein expression in the corpus callosum.ELISA was performed to measure the levels of TNF-α,IL-6,IL-1β and IL-10 in brain homogenates.Immunofluo-rescence staining was also used to observe the expres-sion of ionized calcium binding adapter molecule 1(Iba1)and neural-glial antigen 2(NG2).RT-qPCR and Western blot were conducted to assess the mRNA and protein expression levels of MBP,iNOS,COX-2,JAK2 and STAT3.Results Mice in the CPZ+NS group showed a significant decrease in body weight,cognitive behavior abnormalities,and impaired myelin regeneration.The expression of pro-inflammatory fac-tors increased,while anti-inflammatory factors de-creased.Additionally,Iba1 and NG2 expression in-creased,and the JAK2/STAT3 signaling pathway was activated.After GLPS intervention,the mouse body weight increased,myelin regeneration occurred,cogni-tive behavior was improved,the expression of inflamma-tory factors decreased,anti-inflammatory factors in-creased,NG2 expression was further elevated,and the proliferation of microglia as well as the activation of the JAK2/STAT3 signaling pathway was inhibited.Conclu-sions GLPS can improve cognitive behavior abnormali-ties and inflammatory responses in chronic demyelinated mice by inhibiting the JAK2/STAT3 signaling pathway,thereby promoting myelin repair and regeneration.

Objective This study aimed to investigate the antimicrobial resistance profiles of bacterial strains isolated from pediatric intensive care units(PICU)in China for better antimicrobial therapy.Methods Clinical isolates were collected from 17 institutions,including tertiary care children's hospitals and pediatric department of tertiary general hospitals in China from January 1,2020 to December 31,2022.Antimicrobial susceptibility testing was carried out according to a unified protocol using Kirby-Bauer method or automated systems.Results were interpreted according to the breakpoints released by the Clinical and Laboratory Standards Institute(CLSI)in 2020.Results A total of 10 688 isolates were collected,including gram-positive organisms(39.2％)and gram-negative organisms(60.8％).The top three organisms were S.aureus(13.6％,1 453/10 688),A.baumannii(10.0％,1 067/10 688),and coagulase-negative Staphylococcus(9.9％,1 058/10 688).Multi-drug resistant organisms(MDROs)were very common in children.The prevalence of methicillin-resistant Staphylococcus aureus(MRSA),carbapenem-resistant Enterobacterales(CRE),carbapenem-resistant E.coli,carbapenem-resistant K.pneumoniae(CRKP),carbapenem-resistant A.baumannii(CRAB),and carbapenem-resistant P.aeruginosa(CRPA)was 41.1％,19.4％,8.8％,30.9％,67.4％,and 28.8％,respectively.Overall,more than 50％of Enterobacteriales isolates were resistant to cephalosporins,while nearly 25％of Enterobacteriales isolates were resistant to carbapenems.MDROs were highly resistant to commonly used antibiotics.More than 80％of CRE and CRAB strains were resistant to all beta-lactam antibiotics.CRE and CRAB showed low resistance rates to tigecycline and polymyxin.CRPA showed lower resistance rates to piperacillin,beta-lactamase inhibitor combinations than the resistance rates to third and fourth generation cephalosporins.All of the Staphylococcus and Enterococcus isolates were susceptible to vancomycin and tigecycline.None of PRSP strains isolated from meningitis and nonmeningitis samples were resistant to rifampicin,vancomycin,or linezolid.The prevalence of β-lactamase-negative ampicillin-resistant(BLNAR)strains was 43.3％in Haemophilus influenzae.Conclusions MDROs were prevalent in PICU.It is necessary to establish an effective multidisciplinary team(MDT)to control the antimicrobial resistance.

Objective:To compare the differences in the evaluation of hemolysis performance of cellulose hemostatic materials using different detection methods and test media,and to explore a m ore reasonable testing plan for such products.Methods:Hemolysis tests were conducted on cellulose hemostatic materials using the absorbance measurement hemolysis method and hemoglobin concentration measurement hemolysis method in accordance with YY/T 1651.1-2019 standard.We compared the changes in hemolysis rate,pH value,and osmotic pressure under different experimental media.Results:Under the same experimental method,compared to SC,the hemolysis results using PBS as the extraction medium are smaller,and the changes in pH and osmotic pressure are closer to the normal range of human body changes.Conclusions:The changes in pH and osmotic pressure may be one of the reasons for the high hemolysis rate of cellulose hemostatic materials.Choosing PBS with buffering effect as the leaching medium may be more suitable for evaluating the hemolysis performance of cellulose hemostatic materials.

The intestine and liver are closely connected both physiologically and pathologically, forming a so-called gut-liver axis, with the gut microbiota serving as a pivotal link in their bidirectional communication. Gut microbiota dysbiosis and gut-liver axis disruption play a key role in the development and progression of colorectal cancer liver metastasis (CRLM), though the underlying mechanisms have not been clearly elucidated. Certain gut microbiota, such as Escherichia coli and Enterococcus spp., can breach the intestinal barrier and translocate to the liver, promoting the formation of pre-metastatic niche. Fusobacterium nucleatum and Enterococcus faecalis enhance tumor cell invasion/migration, while Parabacteroides spp. suppress anti-tumor immunity in the liver TME. Interventions like fecal microbiota transplantation, dietary modifications, and traditional Chinese medicine have shown potential in clinical and preclinical studies to improve patient outcomes by targeting the gut microbiota, but their long-term efficacy and safety require further investigation. Future research should focus on elucidating the effects of specific bacterial species, metabolites, viruses, and fungi on tumorigenesis. Exploring the potential of gut microbiota-based precision medicine and personalized therapies will improve risk stratification and enable more targeted interventions for CRLM patients.

Objective:To investigate the protective effect of achyranthes bidentata(AB)on sperm quality in mice with sper-matogenic disorder through the glycolytic metabolic pathway and its action mechanism.Methods:We equally randomized 40 Kun-ming mice into a normal control,a model control,a low-dose AB(3.5 g/kg)and a high-dose AB group(7.0 g/kg),and established the model of spermatogenic disorder in the latter three groups of mice by intraperitoneal injection of doxorubicin(30 mg/kg).Two days after modeling,we collected the testis and kidney tissues and blood samples from the mice for observation of the pathological changes in the testis tissue by HE staining,detection of perm motility with the sperm quality analyzer,examination of the apoptosis of testis cells by flow cytometry,measurement of the levels of testosterone(T),malondialdehyde(MDA),superoxide dismutase(SOD)and cata-lase(CAT)in the serum and testis tissue by ELISA,and determination of expressions of the key enzymes of glycolysis hexokinase Ⅱ(HK2),pyruvate kinase M2(PKM2),platelet phosphofructokinase(PFKP),lactate dehydrogenase A(LDHA)and the meiosis pro-teins REC8 and SCP3 by Western blot,and the mRNA expressions of glycolytic phosphofructokinase 1(PFK1),phosphoglycerate ki-nase 1(PGK1),tumor necrosis factor-α(TNF-α)and interleukin-1 β(IL-1β)by fluorescence quantitative PCR(FQ-PCR).Results:Compared with the model controls,the mice in the AB groups showed significant increases in the testis coefficient,kidney in-dex,sperm concentration,sperm motility,spermatogonia,primary spermatocytes,spermatids,sperm count and the serum T level(P＜0.05 orP＜0.01),but dramatic decreases in the apoptosis of testis cells and percentage of morphologically abnormal sperm(P＜0.01).Achyranthes bidentata also significantly elevated the levels of SOD and CAT,and down-regulated the mRNA expressions of MDA,TNF-α and IL-1β(P＜0.05 or P＜0.01),and up-regulated the protein expressions of HK2,PKM2,PFKP,LDHA,REC8 and SCP3,and expressions of the glycolysis key genes Pfk1 and Pgk1(P＜0.05 orP＜0.01).Conclusion:Achyranthes bidentata ameliorates doxorubicin-induced spermatogenic disorder in mice by regulating the glycolytic pathway and reducing oxidative stress and the expressions of inflammatory factors.

Aim To explore the effect of hydroxysafflor yellow A(HSYA)on lipocalin 2(LCN2)-induced fer-roptosis in HT22 cells and the related mechanism.Methods Thirty male Sprague-Dawley(SD)rats were used to establish the middle cerebral artery occlu-sion/reperfusion(MCAO/R)model by the suture method.The rats were randomly divided into the Sham group,the MCAO/R group,and the MCAO/R+HSYA group.The infarct area was measured by TTC staining,and the degree of neurological deficit was evaluated by the Z-Longa scoring method.The expressions of LCN2 and 24P3R in brain tissues were detected by Western blot.LCN2 protein was added to HT-22 cells,and the cells were divided into the normal group,the LCN2 group,and the LCN2+HSYA group.The optimal con-centration of LCN2-induced neuronal ferroptosis was screened by LDH assay and Western blot,and the ex-pression levels of ferritin,FPN1,GPX4,SLC7A11,COX2,and 24P3R were detected.LCN2 was knocked down by siRNA transfection,and the expressions of GPX4 and ferritin were detected.The contents of glu-tathione(GSH),malondialdehyde(MDA),GPX4,and Fe2+were determined by colorimetry,and the expres-sion of GPX4 was detected by immunofluorescence.The binding force between HSYA and LCN2 was ana-lyzed by molecular docking technology.Results Ani-mal experiments showed that HSYA could reduce the cerebral infarction area and decrease the neurological function score of MCAO/R rats.Compared with the sham group,the levels of LCN2 and 24P3R increased in the MCAO/R group,while HSYA inhibited their ex-pressions.Cell experiments showed that the optimal concentration of LCN2 to induce ferroptosis in HT22 cells was 2 μmol·L-1.After knocking down LCN2 by siRNA transfection,compared with the LCN2 group,the expression levels of GPX4 and ferritin in the siLCN2 group increased significantly.Compared with the nor-mal group,the expressions of SLC7A11,GPX4,FPN1,ferritin,and GSH in the LCN2 group decreased signifi-cantly,while the concentration of Fe2+,and the expres-sions of MDA,COX2,and 24P3R increased.HSYA could increase the expressions of SLC7A11,GPX4,FPN1,ferritin,and GSH,reduce the contents of Fe2+and MDA,and inhibit the expressions of COX2 and 24P3R.Molecular docking showed that the binding en-ergy between HSYA and LCN2 was-8.0 kJ·mol-1.Conclusion HSYA can inhibit LCN2-induced ferrop-tosis in HT22 cells through the SLC7A11/GPX4 signa-ling pathway.