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.

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 design the pyrimidoindole deriva-tive N-butyl-9H-pyrimido[4,5-b]indole-2-carboxamide(BFPI)and synthesize it to investigate whether it in-hibits macrophage pyroptosis and foaming effects through the NLRP3/Caspase-1 pathway.Methods BFPI was synthesized using 2,4,6-triethoxycarbonyl-l,3,5-triazine and 2-aminoindole as starting materials and structurally characterized by 1H NMR,13C NMR,and ESI-MS.The in vitro cultured mouse monocyte macro-phage cell line RAW264.7 was divided into blank,model(PA)and therapeutic(BFPI)groups,and the cells in each group were treated with the corresponding culture medium for 24 h.The proliferative viability was detected by MTT assay,and the formation of intracel-lular lipid droplets was detected by oil red O staining,and NLRP3 was detected by Western-blot and RT-qPCR,caspase-1 and MCP-1 mRNA and protein ex-pression levels by Western blot and RT-qPCR.Results Compared with the blank group,the proliferation vi-ability of cells in the model group significantly de-creased and the formation of lipid droplets significantly increased;compared with the model group,the prolif-eration viability of cells in the treatment group signifi-cantly increased and the formation of lipid droplets sig-nificantly decreased,and the differences were statisti-cally significant(P＜0.01);compared with the blank group,the cellular NLRP3,caspase-1 and MCP-1 mR-NA and protein expression levels of cells in the model group significantly increased;compared with the model group,the expression levels of the above indexes of the cells in the treatment group significantly decreased,and the difference was statistically significant(P＜0.01).Conclusions BFPI contributes to delaying macrophage-derived foam cell formation during athero-genesis by inhibiting macrophage NLRP3,caspase-1,and MCP-1 expression and thereby promoting their pro-liferation and inhibiting lipid phagocytosis.

Major depressive disorder(MDD)is a prevalent con-dition associated with substantial impairment and low remission rates.Traditional antidepressants demonstrate delayed effects,low cure rate,and inadequate therapeutic effectiveness for man-aging treatment-resistant depression(TRD).Several studies have shown that ketamine,a non-selective N-methyl-D-aspartate receptor(NMDAR)antagonist,can produce rapid and sustained antidepressant effects.Ketamine has demonstrated efficacy for reducing suicidality in TRD patients.However,the pharmaco-logical mechanism for ketamine's antidepressant effects remains incompletely understood.Previous research suggests that the an-tidepressant effects of ketamine may involve the monoaminergic,glutamatergic and dopaminergic systems.This paper provides an overview of the pharmacological mechanism for ketamine's anti-depressant effects and discuss the potential directions for future research.

Aim To establish a gait analysis system based on DeepLabCut(DLC)algorithm for evaluating motor function in aged mice.Methods Based on DLC algorithm in deep learning technology,treadmill device and fully closed design were used in the system,including software and hardware.This system was applied to evaluate gait characteristics of mice due to aging un-der different movement modes.Correlation analysis was used to explore the effects of body weight and body length on gait indica-tors.Results This system realized the synchronous analysis of three-dimensional gait(lateral and ventral plane)of mice at specific gait speed,and automatically quantified 47 gait indica-tors.Using this system,it was found that during walking(15 cm·s-1),the standard deviation of body turning angle decreased,forelimb sway duration,standard deviation of knee angle,mean outward angles of left and right hind paw increased in 8 and 15 month-old mice,compared with 2-month-old mice.However,15-month-old mice showed decreased walking frequency,and in-creased stride width,total duration of double support,and knee extension and contraction distance.In addition,at trot(20 cm·s-1),15-month-old mice were unable to walk steadily,and 8-month-old mice had increased total duration of double support and mean outward angles of left hind paw,compared with 2-month-old mice.Correlation analysis revealed that indicators like walking frequency,stride width,forelimb sway duration,total duration of double support,standard deviation of knee an-gle,knee extension and contraction distance,were not affected by changes in body weight and body length.Conclusions The gait analysis system based on DLC algorithm can achieve a more sensitive,accurate and comprehensive evaluation of the gait of aged mice,distinguishing the gait characteristics of aged mice to maintain gait stability,and selecting behavioral indicators that better reflect the gait changes of aged mice.It provides a meth-odological basis for more effective assessment of efficacy and side effects of drugs for anti-aging and anti-decline of motor coordina-tion in the future.

Aim To investigate the preventive and therapeutic effects of the mfat-1 gene therapy on exper-imental autoimmune encephalomyelitis in mice.Meth-ods mfat-1 gene therapy was used to render the host endogenous capability of producing ω-3 PUFAs,con-comitantly reduce the levels of ω-6 PUFAs,and change the proportion of ω-3/ω-6 PUFAs.Then,the levels of PUFAs in blood were analyzed by gas chromatography.The neurological deficits in mice were evaluated by neurological dysfunction score.HE staining and LFB staining of mouse spinal cord slices were used to ob-serve central nervous system inflammation infiltration and demyelinating lesions.Flow cytometry microsphere microarray technology was used to detect the content of cytokines in serum.Results The mfat-1 gene therapy could significantly raise the proportion of ω-3/ω-6 PU-FAs(P＜0.05),markedly delay the incubation period and peak period and reduce neurological dysfunction scores(P＜0.05),and improve inflammation and de-myelination of spinal cords(P＜0.05).It could also greatly increase the levels of IL-2,IFN-γ,IL-4 and IL-17 in serum(P＜0.05).Conclusion The pro-portion of ω-3/ω-6 PUFAs in blood circulation en-hanced by mfat-1 gene therapy can effectively prevent and treat experimental autoimmune encephalomyelitis in mice.

Glutamate,norepinephrine,and their receptors com-prise the glutamatergic and norepinephrine systems,which mu-tually affect each other and play essential roles in mediating vari-ous neuropsychiatric diseases.This paper reviews the functions of N-methyl-D-aspartate receptor(NMDA-R)and α2-adrenergic receptor(α2-AR)and their functional crosstalk at the molecular level in brain in common neuropsychiatric diseases,which would benefit our understanding of neuropathophysiology of psychiatric diseases,drug development and optimization of clinical neuro-psychopharmacology.

Objective The rabbit knee osteoarthritis(KOA)model was established by simple anterior cruciate ligament disruption.Methods The selected 40 adult white rabbits were randomly divided into two groups,blank group with 6 rabbits and model group with 34 rabbits.The rabbits in model group were given the disruption of anterior cruciate ligament of right knee joint.In the fourth,eighth and the twelfth weeks of modeling,different degrees of degenerative changes have been ob-served on the rabbits articular cartilages from both macroscopic and microscopic aspects.Results At 4,8 and 12 weeks after modeling,the articular cartilage of the rabbits in the model group showed degenerative changes in different degrees.At 8 and 12 weeks,the typical pathological manifestations of KOA in the middle and late stages were found in the infrapatellar fat pad and synovium,respectively.There were no changes in articular cartilage,infrapatellar fat pad and synovial membrane in the blank group at the same time.There were significant differences in the gross score between the model group and the blank group at 4 weeks[(1.300±0.674)vs 0.000],8 weeks[(2.400±0.516)vs 0.000]and 12 weeks[(3.583±0.668)vs 0.000](P＜0.05),the histopathological scores were significantly different,at 4 weeks[(2.900±0.567)vs 0.000],8 weeks[(7.500±1.178)vs(0.500±0.707)],12 weeks[(11.833±1.337)vs(1.500±0.707)],(P＜0.05).Conclusion The establishment of rabbit knee arthritis model by simply cutting the anterior cruciate ligament is simple and feasible,with good stability,high success rate,small trauma,short modeling cycle and less changes in animal physiological structure.The rabbit knee arthritis model es-tablished by simply cutting the anterior cruciate ligament has good modeling effect on different stages and grades of knee os-teoarthritis,and the postoperative infection and trauma can be controlled,which can meet the test requirements.

Transcatheter aortic valve replacement(TAVR)has emerged as a promising therapeutic alternative for addressing aortic valve-related pathologies.However,the occurrence of rapid arrhythmias linked to TAVR procedures is progressively drawing scrutiny.Presently,pharmacologic interventions constitute the mainstay of managing atrial arrhythmias related to TAVR,while the potential of ablation as a viable treatment modality remains undefined.Notably,in cases where the arrhythmia's genesis is presumed to be intricately linked to the prosthetic valve,the practicality and safety of ablation procedures remain unverified.Our institution has successfully ventured into radiofrequency ablation for a distinctive patient presenting with this intricate condition,thereby tentatively affirming the efficacy and safety of catheter ablation administered on the surface of prosthetic valves.

Objective:To deeply explore the decision-making experience of patients participating in clinical trials of neoadjuvant immunotherapy for lung cancer.Methods:Using the descriptive and qualitative research, 15 lung cancer patients who participated in clinical trials of neoadjuvant immunotherapy at the Cancer Hospital of the Chinese Academy of Medical Sciences were selected by purposive sampling from April 2021 to August 2022 for semi-structured in-depth interviews. Content analysis method was used for data analysis, summarization, and induction.Results:Three themes were extracted, namely decision-making information dilemma (insufficient or overloaded information, difficulty in understanding professional information, urgent need for decision-making information assistance), complex emotional experience (negative emotional experience, positive emotional experience), and hope for multi-party support (expecting psychological communication, hoping for family understanding, and longing for social recognition) .Conclusions:The decision-making experience of patients in clinical trials of neoadjuvant immunotherapy for lung cancer were summarized and described, which can help strengthen the understanding of the research team and medical and nursing staff on the live experience of such patients when making decisions, provide targeted decision support strategies, and promote good informed consent of patients.