ObjectiveTo investigate the value of predictive models established based on machine learning methods in predicting the risk of metabolic associated fatty liver disease （MAFLD）， and to analyze its key risk factors. MethodsA retrospective analysis was performed for the 50 variables of 2 168 healthy individuals who underwent physical examination in Department of Health Assessment， Xiyuan Hospital， China Academy of Chinese Medical Sciences， from January 2021 to December 2024， including body composition， past history， and laboratory tests， and according to whether they were diagnosed with MAFLD or not， they were divided into MAFLD group with 265 individuals and non-MAFLD group with 1 903 individuals. The Mann-Whitney U test was used for comparison of continuous data between two groups， and the chi-square test was used for comparison of categorical data between two groups. Randomly split the research data into a training set and a validation set in a 70% to 30% ratio. Predictive factors were screened from the training set data using univariate analysis， LASSO regression， and multivariate Logistic regression analysis. Predictive models were then constructed using seven machine learning methods： Logistic regression， decision tree， random forest （RF）， eXtreme gradient boosting， light gradient boosting machine， support vector machine， and artificial neural network. Model performance was evaluated by plotting receiver operating characteristic curve for the validation set and calculating the area under the curve （AUC）， sensitivity， specificity， and Youden index for each model. Furthermore， the SHapley Additive exPlanation （SHAP） method was used to analyze the contribution of variables in the optimal model. ResultsThe prevalence rate of MAFLD among the 2 168 subjects was 12.22% （265/2 168）. Smoking， diastolic blood pressure， phase angle， visceral fat area， muscle fat ratio， waist-to-hip ratio， aspartate aminotransferase， non-HDL-C/HDL-C ratio， triglyceride-glucose index， and gallstones were independent risk factors for MAFLD （all P<0.05）. The seven predictive models of support vector machine， eXtreme gradient boosting， decision tree， light gradient boosting machine， artificial neural network， RF， and Logistic regression had an AUC of 0.738， 0.754， 0.757， 0.786， 0.795， 0.796， and 0.815， respectively， in the validation set， among which the RF model had the best discriminatory ability （AUC=0.796， 95% confidence interval： 0.754 — 0.839）， with a sensitivity of 81.01%， a specificity of 63.16%， and a Youden index of 44.17%. The SHAP analysis showed that visceral fat area， waist-to-hip ratio， and diastolic blood pressure were the top three predictive factors in terms of importance. ConclusionThe RF model， constructed based on body composition and clinical indicators， has a good performance in predicting the risk of MAFLD， and its interpretability can help to identify high-risk individuals in the early stage in clinical practice.

Inteins are unique protein insertion sequences capable of self-excision, enabling the covalent ligation of flanking extein peptides via amide bond formation. This process proceeds spontaneously without requiring external enzymes, cofactors, or chemical reagents, granting inteins exceptional biocompatibility and traceless performance in protein engineering applications. Split inteins represent a specialized and versatile subclass whose splicing domains are encoded by two separate gene fragments rather than a single continuous open reading frame. These fragments, known as the N-terminal (IntN) and C-terminal (IntC) split inteins, associate through non-covalent interactions including hydrophobic forces, hydrogen bonds, and van der Waals forces to assemble into an active three-dimensional structure, which then drives efficient extein ligation and enables protein trans-splicing. Protein trans-splicing mediated by split inteins has become a cornerstone for traceless protein ligation owing to its high specificity and irreversibility, fundamentally reshaping strategies for protein modification, assembly, and functional regulation. Compared with traditional chemical ligation methods, split intein systems require no complex chemical derivatization of peptide fragments and can operate efficiently at micromolar concentrations under physiological conditions, thus avoiding structural and functional damage caused by organic reagents. In contrast to enzymatic ligation tools such as sortase, split inteins eliminate the need for additional enzymes or cofactors, simplifying reaction systems, reducing costs, and minimizing non-specific side products. These distinctive advantages render split inteins highly promising for applications in chemical biology, synthetic biology, and biopharmaceutical development. In recent years, deepened mechanistic understanding has established structure-guided rational design as the primary approach to overcoming key limitations of split inteins, including intrinsic aggregation propensity, strict extein sequence dependence, and limited splicing efficiency. Bioinformatic tools have been used to identify aggregation-prone regions in the IntN fragment, and site-directed mutagenesis of hydrophobic residues, relocation of split sites, or removal of misfolding-prone sequences has substantially reduced in vitro aggregation and improved soluble expression and assembly activity. Rational engineering of catalytic residues and adjacent flexible loops has relaxed strict amino acid preferences at extein junctions, enhancing sequence tolerance and reducing the risk of functional impairment in target proteins. Consensus design based on multiple sequence alignments has yielded ultra-fast splicing variants such as Cfa DnaE and Cat-TerL, which exhibit significantly accelerated kinetics and improved tolerance to denaturing conditions. Meanwhile, advances in structural biology have further clarified the conformational dynamics and catalytic mechanisms of splicing, supporting the precise design of high-performance intein modules. On this basis, electrostatic interaction tuning and metagenomic screening have yielded multiple mutually orthogonal split intein pairs, enabling selective multi-fragment protein ligation and providing new routes for the efficient synthesis of large multi-domain functional proteins. With these engineered split inteins offering continuously improved performance and expanded applicability, protein trans-splicing has been widely applied in numerous cutting-edge areas of protein research and biomedicine. In gene delivery, split intein-based systems overcome the packaging limit of adeno-associated viral vectors, enabling the accurate reconstitution of large therapeutic proteins and base editors in target cells, thereby enhancing the efficacy and scope of gene therapy for genetic diseases. In internal protein sequence editing, split inteins mediate precise sequence replacement and modification in flexible regions or loops of target proteins, without the need for complex multi-step ligation and protein refolding involved in traditional protein semisynthesis. In protein-protein interaction studies, intein-mediated splicing covalently captures transient and weak intracellular complexes, enabling sensitive, high-throughput interaction detection and drug screening. In synthetic biology, conditionally controllable splicing systems support the construction of diverse intracellular and cell-surface biological logic gates for the precise regulation of cellular behavior. In mechanistic biochemical research, split inteins enable photocatalytic proximity labeling and site-specific tagging, allowing the preparation of homogeneous protein samples carrying precise post-translational modifications such as ubiquitination and polyglutamylation for chromatin interactome analysis and epigenetic studies. Moreover, covalent trapping strategies using split inteins stabilize transient enzymatic intermediates, providing unprecedented insights into molecular mechanisms such as nucleosome ubiquitination that are difficult to elucidate using conventional methods. This review systematically summarizes key technological advances in split inteins over the past decade, highlighting engineering strategies, mechanistic insights, and the development of orthogonal components. It comprehensively surveys emerging applications at the frontiers of protein research, analyzes current core challenges, and proposes future directions, particularly emphasizing artificial intelligence-driven de novo design and novel splicing pathways to break existing technical bottlenecks. By enabling traceless, efficient, and versatile protein manipulation, split inteins continue to serve as indispensable tools that drive innovation in protein engineering and fundamental life science research.

Objective:To evaluate the cost-effectiveness and impact on mortality of health management services for the elderly aged 65 years and older in national essential public health service project.Methods:Based on the data of county-level medical institutions in Henan Province from 2019 to 2024,the Random Forest Method was used to construct a counterfactual framework to predict the hospitalization expenses under the unmanaged scenario,and then the cost-benefit ratio(BCR)and net income were calculated.Time-dependent Cox proportional hazards model was used to evaluate the effect of health management on all-cause mortality and cardiovascular and cerebrovascular disease mortality in the elderly.Results:A total of 962 955 elderly patients were included,451 119(46.85%)were included in the management group.The average hospitalization cost of the management group was significantly lower than that of the non-management group(P<0.05).Except for 2020-2021,BCRS in 2019 and 2022-2024 were 6.34,2.05,4.45 and 6.60,respectively.The risk of all-cause death was reduced by 76.96%,and the risk of cardiovascular and cerebrovascular death was reduced by 75.57%in the elderly patients included in the management group compared with those not included in the management group.Suggestions:It is necessary to establish a health outcomes-based evaluation system and promote the transformation and upgrading of the service model from single chronic disease management to"integrated health services with multi-disease management".

Objective To identify the mutation in pathogenic genes by analyzing the clinical features and genotype of a family with Al-port syndrome,in order to provide a theoretical basis in genetic counseling for guidance on the future pregnancies in this couple.Meth-ods Based on closely combined thorough re-examination for the report of previous whole-exome sequencing of the proband and the mu-tation site information,Sanger sequencing verification was conducted in the proband's family members.Additionally,a comprehensive assessment of the proband's clinical manifestations and family history was performed,and the previous whole-exome sequencing report was reanalyzed accordingly.Results In terms of the heterozygous mutation(NM_0000924:c.3289+1G＞A)in intron 35 of COL4A4 gene carried by the proband,this mutation was identified in the proband's father(Ⅲ7),grandmother(Ⅱ6),aunt(Ⅲ6),and two great-uncle(Ⅱ2 and Ⅱ5).All of them exhibited clinical manifestations carried the COL4A4:c.3289+1G＞A heterozygous mutation.However,no mutation was detected in the proband's mother(Ⅲ8),great-grandmother(Ⅰ2),great-aunt(Ⅱ3),and great-uncle(Ⅱ4),grandfather(Ⅱ7)who were clinically unaffected.Additionally,a heterozygous mutation(COL4A3:NM_000914:c.1956A＞G)was identified in ex-on 27 of the COL4A3 gene in the proband.Her mother(Ⅲ 8),the other grandmother(Ⅱ9)and aunt(Ⅲ9)all carried the mutation of COL4A3 but had no clinical manifestation.However,her father(Ⅲ7)did not carry this mutation.Conclusion The splicing site muta-tion COL4A4:NM_0000924:c.3289+1G＞A should be confirmed as the pathogenic cause of Alport syndrome in this family.The combi-nation of whole-exome high-throughput sequencing and Sanger sequencing can effectively diagnose Alport syndrome and provide genetic counseling for the couple's next pregnancy.

AIM To establish an HPLC-MS/MS method for the simultaneous content determination of gallic acid,protocatechuic acid,oxypaeoniflorin,catechin,epicatechin,albiflorin,paeoniflorin,rutin,calycosin-7-glucoside,syringaldehyde,ferulic acid,coumarin,ononin,calycosin,cinnamic alcohol,cinnamic acid,benzoylpaeoniflorin,cinnamaldehyde,astragaloside,astragaloside Ⅲ,6-gingerol in Huangqi Guizhi Wuwu Decoction.METHODS The analysis was performed on a 30 ℃ thermostatic Thermo Scientific Hypersil GOLD column(150 mmx4.6 mm,3 μm),with the mobile phase comprising of 0.015％formic acid-acetonitrile flowing at 0.4 mL/min in a gradient elution manner,and electrospray ionization source was adopted in positive and negative ion modes with multiple reaction monitoring.RESULTS Twenty-one constituents showed good linear relationships within their own ranges(r＞0.990 5),whose average recoveries were 93.99％-108.52％with the RSDs of 1.04％-5.97％.CONCLUSION This simple,feasible,stable and reliable method can be used for the quality control of Huangqi Guizhi Wuwu Decoction.

Objective To identify the mutation in pathogenic genes by analyzing the clinical features and genotype of a family with Al-port syndrome,in order to provide a theoretical basis in genetic counseling for guidance on the future pregnancies in this couple.Meth-ods Based on closely combined thorough re-examination for the report of previous whole-exome sequencing of the proband and the mu-tation site information,Sanger sequencing verification was conducted in the proband's family members.Additionally,a comprehensive assessment of the proband's clinical manifestations and family history was performed,and the previous whole-exome sequencing report was reanalyzed accordingly.Results In terms of the heterozygous mutation(NM_0000924:c.3289+1G＞A)in intron 35 of COL4A4 gene carried by the proband,this mutation was identified in the proband's father(Ⅲ7),grandmother(Ⅱ6),aunt(Ⅲ6),and two great-uncle(Ⅱ2 and Ⅱ5).All of them exhibited clinical manifestations carried the COL4A4:c.3289+1G＞A heterozygous mutation.However,no mutation was detected in the proband's mother(Ⅲ8),great-grandmother(Ⅰ2),great-aunt(Ⅱ3),and great-uncle(Ⅱ4),grandfather(Ⅱ7)who were clinically unaffected.Additionally,a heterozygous mutation(COL4A3:NM_000914:c.1956A＞G)was identified in ex-on 27 of the COL4A3 gene in the proband.Her mother(Ⅲ 8),the other grandmother(Ⅱ9)and aunt(Ⅲ9)all carried the mutation of COL4A3 but had no clinical manifestation.However,her father(Ⅲ7)did not carry this mutation.Conclusion The splicing site muta-tion COL4A4:NM_0000924:c.3289+1G＞A should be confirmed as the pathogenic cause of Alport syndrome in this family.The combi-nation of whole-exome high-throughput sequencing and Sanger sequencing can effectively diagnose Alport syndrome and provide genetic counseling for the couple's next pregnancy.

The Animal Molecular Biology course is a crucial and foundational course for both Animal Medicine and Animal Science majors.Apart from teaching fundamental principles of molecular biology,the course provides updated applications of these principles in the field of animal science research.Im-portantly,it plays a fundamental role in cultivating students'research capabilities.With the rise of over-whelming information and their optimal utilization,the demand for integrating digital education with tradi-tional teaching methods is increasing.Based on the five years of teaching practice,this paper summarizes four highlights of the course:the construction of teaching resource,the restructuring of teaching syllabus,the adjustment of classroom teaching hours,and the improvement of assessment methodology.It focuses on Electronic-Learning"E(E-Learning)",offline classroom intensive teaching"C(Classroom)",and post-class extension to construct a blended teaching model that integrates Electronic-Learning and Class-room teaching,namely the"E+C"blended teaching model.Offline classroom teaching emphasizes the combination of theory and knowledge systems,while online Electronic-Learning mainly focuses on popular science and interesting aspects to stimulate students' interests and enthusiasm in learning.Over five years of practice,the"E+C"blended model has been proven to exert a good teaching effect.Students have reported significant gains from the course,with tightly connected and strongly complementary class-room teaching and E-Learning,which greatly aids in mastering professional knowledge.It also cultivates intrinsic motivation for learning and enhances the sense of accomplishment in acquiring knowledge,sig-nificantly improving teaching effectiveness.

Objective:To evaluate the cost-effectiveness and impact on mortality of health management services for the elderly aged 65 years and older in national essential public health service project.Methods:Based on the data of county-level medical institutions in Henan Province from 2019 to 2024,the Random Forest Method was used to construct a counterfactual framework to predict the hospitalization expenses under the unmanaged scenario,and then the cost-benefit ratio(BCR)and net income were calculated.Time-dependent Cox proportional hazards model was used to evaluate the effect of health management on all-cause mortality and cardiovascular and cerebrovascular disease mortality in the elderly.Results:A total of 962 955 elderly patients were included,451 119(46.85%)were included in the management group.The average hospitalization cost of the management group was significantly lower than that of the non-management group(P<0.05).Except for 2020-2021,BCRS in 2019 and 2022-2024 were 6.34,2.05,4.45 and 6.60,respectively.The risk of all-cause death was reduced by 76.96%,and the risk of cardiovascular and cerebrovascular death was reduced by 75.57%in the elderly patients included in the management group compared with those not included in the management group.Suggestions:It is necessary to establish a health outcomes-based evaluation system and promote the transformation and upgrading of the service model from single chronic disease management to"integrated health services with multi-disease management".

Objective:An in vivo mammalian hepatocyte Unscheduled DNA Synthesis(UDS)test was used to evaluate the genotoxicity of Cross-linked Sodium Hyaluronate Gel and Bone Repair Materials,providing experimental evidence for establishing a UDS testing method for medical devices and materials.Methods:0.9％sodium chloride injection and cottonseed oil were used as the solvent for test materials and negative control,respectively.N-dimethylnitrosamine(NDMA)was used as the positive control for the early sampling times,and 2-acetylaminofluorene(2-AAF)was used as the positive control for the late sampling times.SD rats were administered a single dose for toxic exposure,and liver tissues were collected at 4 h and 16 h,respectively.Hepatocytes were isolated using collagenase perfusion.After labeling with 5-ethynyl-2'-deoxyuridine(EdU),and the net average fluorescence intensity(NAFI)of cell nuclei and nucleoplasm was measured by fluorescence microscope.Data from 50 cells were used to analyze the DNA repair level.Results:Compared with the negative control groups,the positive control groups(NDMA and 2-AAF)showed highly statistically significant differences in NAFI(P＜0.01),indicating successful induction of DNA damage.There was no statistically significant differences between the cross-linked sodium hyaluronate gel groups,bone repair material groups and the negative control group(P＞0.05),suggesting that these materials did not significantly induce DNA damage under the experimental conditions.Conclusion:This study first applied EdU labeling technology to the in vivo hepatic UDS assay,achieving non-radioactive labeling through click chemistry reactions.Under the conditions of this study,cross-linked sodium hyaluronate gel and bone repair materials did not exhibit genotoxicity.In the follow-up,the sample range can be expanded and the observation period can be prolonged to further improve the genotoxicity evaluation system of medical devices.

Objective To study the need for blood compatibility evaluation of medical devices that come into indirect contact with blood in order to accurately evaluate the risk of their interaction with blood.Methods Seven medical devices with indirect contact with blood were selected as samples including extension tubes of central venous catheters,port bodies of implantable drug delivery devices,infusion sets,receiving lines of dialysis equipment,auxiliary lines of left ventricular assist devices,blood monitors and catheter holders,with high-density polyethylene as the negative control,glass beads as the positive control and blank whole blood or plasma for the blank control.Partial thromboplastin time(PTT)test,platelet count test and hematology test(white blood cell and red blood cell count)were performed by direct contact method and indirect contact method,respectively.In the direct contact method,whole blood or plasma was in direct contact with the sample;while in the indirect contact method,whole blood or plasma was not in direct contact with the extraction solution,with no direct contact with the sample.Results With the indirect contact method the ratios(expressed as a percentage)of the PTT,platelate,WBC and RBC counts of the samples,positive and negative controls to those of the blank control were all higher than those with the direct contact method,and the indirect contact method had the sensitivity lower than that of the direct contact method.Conclusion Medical devices indirectly contacting blood have low risks for causing coagulation and platelet and hematologic adverse reactions,which are suggested to be evaluated for hemolysis testing only in case of the history of safe clinical use.[Chinese Medical Equipment Journal,2025,46(8):44-49]