AIM:To observe the changes of atrial fibrillation susceptibility,and the remodeling of atrial myo-cyte action potential,ultrarapid activation delayed rectifier potassium current(IKur)and transient outward potassium cur-rent(Ito)in elderly mice,and to explore the mechanism of atrial fibrillation from the single cell electrophysiological level.METHODS:The C57BL/6J mice were divided into old group(20 months old)and young group(4 months old).Atrial fi-brillation was induced by esophageal atrial pacing.The atrial myocytes were isolated,and action potential and ion currents were recorded with patch-clamp technique.The associated proteins were detected by Western blot technique.RE-SULTS:(1)Compared with young mice,the total incidence of atrial fibrillation was significantly increased in old mice(20.0%at 4 months old vs 60.0%at 20 months old,P<0.01).(2)The action potential duration of atrial myocytes in aged mice was shortened,and more significantly after stimulation.(3)The density of Ito and IKur in atrial myocytes of aged mice increased significantly,from(12.6±1.4)pA/pF to(21.7±1.1)pA/pF,and from(7.5±1.5)pA/pF to(13.3±2.1)pA/pF,respectively(P<0.01).After stimulation,the current increased more significantly,especially in older atrial cells.Compared with the young mice,the steady-state activation curve of Ito in the atrial myocytes of the aged mice shifted towards the depolarization,suggesting that activation of Ito channels in the aged mice increased at the same voltage stimula-tion.(4)Compared with young group,the expression of KV4.2(generating Ito)and KV1.5(generating IKur)proteins in the atrial tissue of the mice in old group was significantly increased,and the expression of caveolin-3 and end-binding protein 1(EB1)was up-regulated,suggesting that the increases in KV4.2 and KV1.5 total channel proteins and effective proteins in the cell membrane might contribute to the increase in the remodeling of potassium currents in the elderly atrial myo-cytes.CONCLUSION:The incidence of atrial fibrillation in elderly mice is significantly augmented,which may be related to the increases in Ito and IKur in atrial myocytes.The remodeling of potassium currents in elderly atrial myocytes is one of the electrophysiological bases leading to the shortening of action potential duration and the occurrence of atrial fibrillation.

Aim To investigate the effect of chrysoeriol on pulmonary vascular remodeling in pulmonary hyper-tension by animal experiments combined with cell ex-periments,and to explore its potential therapeutic tar-gets by network pharmacology.Methods The target of chrysoeriol was collected in Targetnet,SEA and SwissTargetPrediction database.Pulmonary arterial hy-pertension(PAH)targets were collected in the Dis-GeNET and GeneCards databases,and PPI network map was drawn in the STRING database,and key tar-gets were screened.The GO and KEGG pathway en-richment analysis was carried out through DAVID data-base and Weishengxing platform.AutoDock software was used for molecular docking of key core targets.The PAH model of rats was constructed,and the pulmo-nary hemodynamics and vascular remodeling were de-tected by echocardiography,HE and Masson staining.Primary pulmonary smooth muscle cells were extracted,and the effects of drugs on pathway proteins were de-tected in vitro.Results The results of network phar-macology showed that chrysoeriol exerted therapeutic effects on pulmonary hypertension by affecting key tar-gets such as AKT1,SRC,EGFR,MMP9 and gsk3 β,and signaling pathways such as EGFR and PI3K-AKT.Molecular docking showed that chrysoeriol had good binding ability with 5 key target genes.Animal experi-ments showed that the pulmonary hemodynamic func-tion of PAH rats was significantly improved after ad-ministration of chrysoeriol.The remodeling of small pulmonary arteries was significantly reduced.Cell ex-periments showed that chrysoeriol could inhibit the ex-pression of proliferation,migration and phenotypic transformation genes.Conclusion Chrysoeriol may play a role in the treatment of pulmonary hypertension through multiple targets.

OBJECTIVE To study the pharmacokinetics/pharmacodynamics(PK/PD)profiles of meropenem in the plasma,lung,muscle and skin tissues of rabbits,and to explore the effects of sepsis and continuous renal replacement therapy(CRRT)on the probability of target attainment(PTA)of meropenem.METHODS Twenty-four New Zealand rabbits were randomly divided into four equal groups:sepsis-CRRT group,sepsis group,normal-CRRT group and normal control group.Six hours after a rabbit model of sepsis was established via cecal ligation and puncture(CLP)surgery,an auto-matic infusion pump with meropenem[(1 000/60)×3.27=54.5 mg·kg-1,converted from that of humans(1g)to that of rabbits]was used to administer the drug to the animals for 0.5 h,while CRRT was started simultaneously with drug administration in the CRRT group.Microdialysis samples were collected from 4 target sites of each group once every 30 min for 480 min.The concentration of meropenem was deter-mined using liquid chromatography-tandem mass spectrometry(LC-MS/MS)before a concentration-time curve was constructed.Pharmacokinetic parameters such as the peak concentration(Cmax),time to reach peak concentration(Tmax),area under the concentration-time curve(AUC),and elimination half-life(t1/2)were calculated using a non-atrioventricular model.Monte Carlo simulation(MCS)was performed at various minimum inhibitory concentrations(MICs)using pharmacokinetic parameters of meropenem to assess the probability of target attainment(PTA).The predefined PK/PD target was％fT＞4MIC＞40％,where the percentage of time that the free drug concentration[f]exceeded 4 times that of the MIC during a dosing interval was above 40％and Cmax/MIC exceeded 4.RESULTS The results indicated no statistically significant differences between the PK parameters of skin tissue in the normal control group and sepsis group,whereas Cmax of other tissues was significantly lower in the sepsis group than in the normal control group(P＜0.01).AUCplasma and AUCskin were significantly increased(P＜0.01),while AUCIung and AUCmuscle were significantly decreased(P＜0.01)when the sepsis-CRRT group was compared with the sepsis group.With a target value of％fT＞4MIC＞40％,the plasma and skin tissues of the sepsis-CRRT group,the muscle tissues of the normal-CRRT group and the lung,muscle and skin tissues of the normal control group achieved a PTA of over 90％(MIC=1 mg·L-1).The skin tissues of the sepsis-CRRT group and the lung tissues of the normal control group achieved an efficacy target of more than 90％(MIC=2 mg·L-1).However,our results did not indicate that either AUC or Cmax was involved in the changes of PTA in the normal control group.For all tissues except skin tissues(MIC=4 mg·L-1),PTA decreased with Cmax in the sepsis group.The PTA of plasma and skin tissues increased with the AUC,while the PTA of lung(MIC=2,4 mg·L-1)and muscle tissues(MIC=1,2,4 mg·L-1)decreased with the AUC in the sepsis-CRRT group.CONCLUSION Sepsis has little effect on the distri-bution of meropenem in skin tissues.Sepsis may reduce the efficacy of meropenem in various tissues,and CRRT can improve the efficacy of plasma and skin tissues in sepsis.This method of collecting target samples with microdialysis probes is accurate and reliable,which can be used in therapeutic drug monitoring.

During sudden outbreaks of major infectious diseases,traditional vaccine clinical trials often fail to deliver timely and meaningful outcomes.To address this,innovative trial designs are essential to accelerate or restructure the traditional three-phase clinical trial process while maintaining adherence to scientific principles of drug candidate safety and efficacy.This paper presents various innovative vaccine clinical trial designs and concepts,along with critical considerations for their application,to serve as a methodological reference for related research.Adaptive designs provide flexibility by dynamically adjusting trial parameters—such as dose selection,population stratification,and sample size reestimation—based on interim analysis results.Bayesian designs incorporate historical data and prior information,reducing sample size requirements.Master protocol designs enable the evaluation of multiple treatments or target populations within a unified framework,significantly improving efficiency.Additionally,real-world data(RWD),including electronic health records vaccination records and insurance claims,supports the creation of virtual control groups,addressing ethical concerns while enhancing trial feasibility.A hybrid design combining randomized controlled trials(RCTs)with RWD is also proposed to leverage the strengths of both methodologies.These innovative designs optimize the research process,accelerating vaccine development and regulatory approval.By integrating these approaches,robust evidence-based insights can be generated,advancing precision medicine goals and strengthening public health responses to emerging infectious diseases.

This study aims to establish BHK-21 stable cell lines expressing APN from four species(human,pig,dog,and cat),the APN fragments were amplified from pEGFP-C1-APN plasmids of the four species stored in the laboratory to generate the recombinant plasmids pcDNA4.0-APN.Af-ter the recombinant plasmids were transfected into BHK-21 cells,the stable BHK-21 cell lines ex-pressing the APNs were selected by two rounds of limited dilution.The constructed BHK-21 cell lines were identified by indirect immunofluorescence assay(IFA),and their susceptibility to PD-CoV and TGEV was tested for these four cell lines.Virus infection experiments revealed that PD-CoV infected cells expressing human,pig,and dog APNs,while it did not infect cells expressing cat APN.Simultaneously,TGEV infected cells expressing pig,dog,and cat APNs,but did not infect cells expressing human APN.The results suggest that the risk of cross-species infection for different coronaviruses and the established cell line can be used effectively to evaluate the virus in-fection.The findings also revealed that PDCoV has the potential risk of cross-species infection of human and dog,and TGEV has the potential risk of cross-species infection of dog and cat.These results provide a basis for the prevention and control strategy of coronaviruses.

Objective To design a performance testing platform to evaluate the working status and performance characteristics of the ventilator proportional solenoid valve.Methods The performance testing platform had its hardware including a high-pressure gas source,a pressure regulating valve,sensors and etc,and its software designed based on PyQt5 and composed of several modules for data acquisition,parameter setting,image display,indicator computation,result output and etc.Two kinds of proportional solenoid valves(Valve 1、Valve2)were selected for static and dynamic tests to verify the performance of the platform.Results The platform developed facilitated the proportional solenoid valve to carry out accurate computation of static and dynamic indicators at real time and time domain and waveform feature extraction of sensor data by precision control and data acquisition for the proportional solenoid valve.Static tests showed that Valve 1 gained advantages over Valve 2 in static flow characteristics involving in lowered repeatability,return error and offset while enhanced stability;dynamic tests indicated Valve 2 had rapid flow variations and significant flow fluctuation impacts,Valve 1 showed smooth dynamic response changes,and Valve 2 behaved better than Valve 1 in dynamic performance.Conclusion The testing platform developed comprehensively demonstrates the performance characteristics and working performance of the ventilator proportional solenoid valve,which is of great significance to enhance the reliability and safety of the ventilator.[Chinese Medical Equipment Journal,2025,46(1):13-19]

The global burden of obesity and related chronic diseases is increasing,making weight management a core issue in the field of public health.This article systematically reviewed the latest developments in weight management from three dimensions-policy frameworks,technological innovations,and practical models-both domestically and internationally.It summarized existing experiences and key challenges,aiming to provide theoretical references and practical directions for constructing scientific,precise and sustainable weight management strategies.

Medical engineering in TCM medical institutions in Guizhou Province was described in terms of its development status and problems in functional positioning,professional title appraisal,unbalanced staff composition and discipline foun-dation.Some suggestions were put forward including determining the functional positioning and management mode of medical engineering institutions,promoting the professional title system for medical engineering staffs,strengthening medical engineering team and enhancing medical engineering discipline.References were provided for the development of medical engineering in TCM medical institutions in Guizhou Province.[Chinese Medical Equipment Journal,2025,46(5):84-90]

AIM:To observe the changes of atrial fibrillation susceptibility,and the remodeling of atrial myo-cyte action potential,ultrarapid activation delayed rectifier potassium current(IKur)and transient outward potassium cur-rent(Ito)in elderly mice,and to explore the mechanism of atrial fibrillation from the single cell electrophysiological level.METHODS:The C57BL/6J mice were divided into old group(20 months old)and young group(4 months old).Atrial fi-brillation was induced by esophageal atrial pacing.The atrial myocytes were isolated,and action potential and ion currents were recorded with patch-clamp technique.The associated proteins were detected by Western blot technique.RE-SULTS:(1)Compared with young mice,the total incidence of atrial fibrillation was significantly increased in old mice(20.0%at 4 months old vs 60.0%at 20 months old,P<0.01).(2)The action potential duration of atrial myocytes in aged mice was shortened,and more significantly after stimulation.(3)The density of Ito and IKur in atrial myocytes of aged mice increased significantly,from(12.6±1.4)pA/pF to(21.7±1.1)pA/pF,and from(7.5±1.5)pA/pF to(13.3±2.1)pA/pF,respectively(P<0.01).After stimulation,the current increased more significantly,especially in older atrial cells.Compared with the young mice,the steady-state activation curve of Ito in the atrial myocytes of the aged mice shifted towards the depolarization,suggesting that activation of Ito channels in the aged mice increased at the same voltage stimula-tion.(4)Compared with young group,the expression of KV4.2(generating Ito)and KV1.5(generating IKur)proteins in the atrial tissue of the mice in old group was significantly increased,and the expression of caveolin-3 and end-binding protein 1(EB1)was up-regulated,suggesting that the increases in KV4.2 and KV1.5 total channel proteins and effective proteins in the cell membrane might contribute to the increase in the remodeling of potassium currents in the elderly atrial myo-cytes.CONCLUSION:The incidence of atrial fibrillation in elderly mice is significantly augmented,which may be related to the increases in Ito and IKur in atrial myocytes.The remodeling of potassium currents in elderly atrial myocytes is one of the electrophysiological bases leading to the shortening of action potential duration and the occurrence of atrial fibrillation.

Objective:To select low-dose radiation-activated genes with intrinsic radiation protection by developing a model for adaptive responses to low-dose ionizing radiation, in order to explore the mechanisms behind the radiation resistance of the candidate genes.Methods:The cells were divided into adaptive response induction group and whole transcriptome sequencing group. The level of DNA damage was assessed using the γ-H2AX immunofluorescence assay. The low-dose radiation-activated candidate genes with radiation protection were selected through whole transcriptome sequencing and quantitative reverse transcription PCR (RT-qPCR)-based validation. The anti-radiation effect of candidate gene CCND1 was assessed based on CCK-8 cell proliferation and γ-H2AX immunofluorescence assay. After up- and down-regulation of CCND1 expression, the anti-radiation mechanism of CCND1 was preliminarily explored through transcriptome sequencing analysis.Results:A model for low-dose ionizing radiation-induced adaptive responses of lymphocytes was constructed. Using this model, six candidate genes with radiation protection, including CCND1, ZMAT3, MGAT3, DFFB, CYP4F2, ITGA6, were selected. Compared to the control group, overexpressed CCND1 led to significantly enhanced proliferation ability of AHH-1 cells ( t = 7.92-14.76, P < 0.05) and distinctly lowered level of DNA damage ( t = 2.79-9.68, P < 0.05) after 2 Gy of X-ray irradiation. Furthermore, compared to the control group, the CCND1 knockdown caused significantly decreased cell proliferation ability ( t = 13.58-26.25, P < 0.05) and notably elevated level of DNA damage of cells ( t = 2.87-7.61, P < 0.05). Transcriptome sequencing revealed that up- and down-regulation of CCND1 expression resulted in the activation of pathways related to cell growth, death, and damage repair. Conclusions:By selecting six low-dose-activated candidate genes with radiation protection and revealing the function of CCND1 in radiation protection, this study provides a new perspective for the development of radiation protection agents from the perspective of adaptive responses to low-dose radiation.