Objective: To investigate the factors influencing intraoperative blood transfusion in patients with hip fractures and to develop a machine learning (ML) model for predicting this risk. Methods: A total of 424 patients with hip fractures who underwent surgical treatment between November 2022 and March 2025 in our hospital were selected. Key feature variables of intraoperative blood transfusion risk were identified using the Boruta algorithm. Four different ML algorithms—support vector machine (SVM), linear discriminant analysis (LDA), mixed discriminant analysis (MDA), and extreme gradient boosting (XGBoost)—were used to develop predictive models for intraoperative blood transfusion risk. The predictive performance of the four ML models were evaluated using accuracy, precision, receiver operating characteristic (ROC) curves, precision-recall curves (PRC), precision-recall gain curves (PRGC), and F1 scores. Shapley additive interpretation (SHAP) was used to interpret the final model. Results: Among the 424 patients, 77(18.2%) received intraoperative blood transfusion. The Boruta algorithm identified albumin (ALB), activated partial thromboplastin time (APTT), types of anesthesia, types of fracture, and hemoglobin (Hb) as key feature variables for predicting intraoperative blood transfusion risk. In model evaluation, the SVM model outperforms the other three models across multiple metrics, including the area under the receiver operating characteristic curve (AUC), recall, recall gain, accuracy, precision, F1 score, and the area under the precision-recall curve (PRC-AUC). The SVM model, interpreted and visualized based on SHAP values, effectively predicted intraoperative blood transfusion risk in patients with hip fracture. A visual online application was developed based on the SVM model (https://pbo-nomogram.shinyapps.io/blood/). Conclusion: Preoperative low ALB and Hb levels, prolonged APTT, general anesthesia, and intertrochanteric fractures are risk factors for intraoperative blood transfusion in hip fracture patients. The risk prediction model for intraoperative blood transfusion constructed based on the SVM algorithm has optimal performance, which provides new ideas and methods for the clinical early identification of hip fracture patients with high transfusion risk and the implementation of targeted interventions.

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 explore the impact of tumor-associated myeloid cell infiltration signatures on postoperative overall survival (OS) in patients with gastric cancer. Methods A retrospective analysis was performed on patients who underwent radical gastrectomy at Zhongshan Hospital, Fudan University from January 2005 to December 2019. Patients were randomly divided into a training set (n＝167) and an internal validation set (n＝168) at a 1:1 ratio. Meanwhile, 147 patients with gastric cancer treated at Zhongshan Hospital (Xiamen), Fudan University during the same period were enrolled as the external validation set (n＝147). Immunohistochemistry was used in all patients to evaluate the distribution characteristics of 18 immune markers in three regions of gastric cancer tissues, namely primary tumor (PT), invasive margin (IM), and normal tissue (NT). These markers include 11 myeloid cell markers (CD11b, CD33, CD11c, CD14, CD15, CD16, CD68, CD86, CD163, CD206, and CD66b) and 7 immune checkpoints (CD73, IDO, LAG3, PD-1, SIGLEC9, SIRPA, and TIM3). LASSO regression and Cox proportional hazards model were applied to screen immune markers associated with postoperative OS in gastric cancer patients, and a predictive model for 1-, 3-, and 5-year postoperative OS was established. Data from the internal and external validation set were used for internal and external verification of the predictive model. Receiver operating characteristic (ROC) curves were plotted and the area under the curve (AUC) was calculated to assess the discriminative ability of the model. Results In the training set, LASSO regression and Cox proportional hazards model identified 4 immune marker signatures (CD14_PT, CD15_PT, CD206_PT, and SIGLEC9_PT) to construct the predictive model. ROC curve analysis showed that the AUCs of the model for predicting 1-, 3-, and 5-year postoperative OS were 0.74, 0.75, and 0.84, respectively. When the model was applied to the internal and external validation sets, the AUCs for 1-, 3-, and 5-year postoperative OS were 0.74, 0.72, 0.72 (internal validation set) and 0.72, 0.71, 0.74 (external validation set), respectively. Cox multivariate regression analysis showed that the risk score was an independent risk factor for postoperative OS in patients with gastric cancer. Conclusion The model constructed based on LASSO-Cox regression exhibits good predictive performance and can effectively predict postoperative OS in gastric cancer patients, which may serve as a basis for intensive treatment of high-risk patients after surgery.

Objective To evaluate the effectiveness of preoperative immunosuppressive therapy combined with surgical intervention for Behçet's disease. Methods A retrospective study was conducted on Behçet's disease patients who underwent cardiovascular surgery at Guangdong Provincial People's Hospital from 2012 to 2021. Patients were divided into an immunosuppressive group and a non-immunosuppressive group based on whether they received immunosuppressive therapy before surgery. The complications and long-term survival rates of the two groups were analyzed. Results A total of 28 patients were included, among which 2 patients underwent reoperation, a total of 30 surgeries were performed, including 16 males (53.3%), and the age at diagnosis was 37 (31, 45) years. There were 15 surgeries in the immunosuppressive group and 15 surgeries in the non-immunosuppressive group. Compared with the non-immunosuppressive group, the incidence of complications during hospitalization in the immunosuppressive group was lower (13.3% vs. 53.3%, P=0.008). One patient died in hospital, and the rest were discharged and followed up, with a median follow-up time of 38.7 (15.1, 57.3) months, and there was no statistically significant difference in long-term survival rate between the two groups (73.3% vs. 93.3%, P=0.158). There was no statistical difference in the cumulative incidence of complications one month (20% vs. 53%, P=0.058) and one year (27% vs. 60%, P=0.065) after surgery between the immunosuppressive group and the non-immunosuppressive group, but there was a statistical difference in the cumulative incidence of complications three years after surgery (47% vs. 92%, P=0.002). Conclusion Surgical treatment can save lives in Behçet's disease patients with cardiovascular diseases, but the incidence of postoperative complications is high. Timely use of immunosuppressants before cardiovascular surgery can reduce the incidence of postoperative complications.

As an extension of the central nervous system, the retina is the only tissue in the body that allows direct in vivo observation of both neural and vascular structures, offering a unique non-invasive window for the assessment of cerebral neurovascular diseases. Recent studies have shown that multimodal imaging techniques—such as fundus photography, optical coherence tomography(OCT), and OCT angiography(OCTA)—enable quantitative analysis of retinal indicators including vascular caliber, fractal dimension, retinal nerve fiber layer thickness, and microvascular density. These metrics can, to some extent, reflect the severity and progression risk of cerebrovascular and neurodegenerative diseases such as stroke, Alzheimer's disease, and Parkinson's disease. Consequently, retinal imaging holds promise as a powerful tool for early screening, risk stratification, and treatment monitoring. This article systematically reviews the application of retinal imaging technologies in the diagnosis and management of cerebral neurovascular disorders, with a particular focus on the important role of artificial intelligence(AI)-driven image analysis in enhancing screening efficiency, improving risk assessment accuracy, and promoting multidisciplinary collaborative care, thereby providing insights for clinical translation.

Objective: To investigate the health literacy level and its influencing factors among the elderly in Shunyi District, Beijing Municipality, so as to provide the evidence for developing health literacy intervention measures and improving the elderly's health literacy level. Methods: From September to November 2024, permanent residents aged ≥60 years in Shunyi District were selected by a multi-stage random sampling method combined with probability proportionate to size sampling method. The Chinese Elderly Health Literacy Questionnaire was used to conduct face-to-face surveys on basic information, health status, and health literacy. The health literacy level of the elderly was analyzed. Multivariable logistic regression model and decision tree model were used to analyze the influencing factors for health literacy level of the elderly. Results: There were 285 males (47.50%) and 315 females (52.50%). The mean age was (68.91±7.38) years. The health literacy level of the elderly was 14.33%. The literacy levels of basic concepts, basic knowledge, and basic skills were 43.33%, 5.33%, and 50.83%, respectively. The literacy levels of scientific aging concept, intrinsic capacity and geriatric syndromes, healthy lifestyle, information acquisition and self-care, health service utilization and chronic disease management, and safety and first aid were 52.33%, 7.17%, 51.83%, 58.83%, 72.00%, and 4.33%, respectively. Multivariable logistic regression analysis showed that educational level (high school/technical secondary school/technical school and above, OR=2.376, 95%CI: 1.020-5.532), monthly household income per capita (1 000-<3 500 yuan, OR=2.973, 95%CI: 1.349-6.555), residence (urban, OR=3.836, 95%CI: 2.071-7.105), and health attention (relatively concerned, OR=4.164, 95%CI: 1.779-9.742) were influencing factors for health literacy level of the elderly. Decision tree model results showed that educational level, monthly household income per capita, residence, and health attention were influencing factors for health literacy level of the elderly, with residence being the main influencing factor. Elderly people living in urban areas, relatively concerned about health, and with high school/technical secondary school/technical school and above educational level had higher health literacy level (40.00%). Conclusions The health literacy level of the elderly in Shunyi District is mainly affected by educational level, monthly household income per capita, residence, and health attention. It is recommended to focus on rural elderly with lower educational level, monthly household income per capita, and health attention.

Objective To evaluate the diagnostic value of coiled-coil domain containing 83(CCDC83),carcinoembryonic antigen(CEA)and carbohydrate antigen(CA)199 detection in patients with colorectal cancer(CRC).Methods A total of 168 patients with colorectal diseases and 80 healthy physical examination subjects admitted to Hongqi Hospital Affiliated to Mudanjiang Medical University from September 2022 to January 2025 were selected as the study objects.Participants were classified into three groups based on pathological diagnosis and colonoscopy findings:colorectal cancer group(n=80),colorectal benign disease group(n=88),and healthy control group(n=80).Serum samples from all three groups were collected for detection of CCDC83,CEA,and CA199 expression levels.The diagnostic value was analyzed using receiver operating characteristic(ROC)curves.Results Colorectal cancer group exhibited significantly higher expression levels of CCDC83,CEA,and CA199 compared to colorectal benign disease group and healthy control group,with statistically significant differences(P＜0.05).ROC curve analysis demonstrated diagnostic value for CCDC83,CEA,and CA199,with CCDC83 showed superior specificity compared to CEA and CA199.Conclusion CCDC83,CEA and CA199 showed good diagnostic efficacy for colorectal cancer.

Objective:To construct the evaluation indicator system of medical insurance capacity, healthcare service capacity, and pharmaceutical supply security capacity, and explore the process and law of medical-insurance-medicine linkage reform in the 12 years since the Sanming medical reform.Methods:Data from documents such as Development of Healthcare in Sanming City and Financial Performance Report of Public Medical Institutions in Sanming City were collected. The TOPSIS and coupled coordination models were used to measure the degree of medical-insurance-medicine linkage reform, and correlation analysis was employed to explore the relationship between medical insurance capacity, healthcare service capacity, pharmaceuticals supply securty capacity and the degree of medical-insurance-medicine linkage reform.Results:The degree of medical-insurance-medicine linkage reform in Sanming medical reform increased from 0.220 before the reform to the highest of 0.346, 0.642 and 0.831 in the stages of " governing chaos and blocking waste", " establishing rules and systems" and " treating diseases before they occur and promoting general health" respectively. The coupling coordination status advanced from moderate imbalance to sound coordination. The r-values of medical insurance capacity, healthcare service capacity, and pharmaceutical supply security capacity with the degree of medical-insurance-medicine linkage were 0.940, 0.926, and 0.789 respectively ( P<0.01), among which medical insurance had the highest correlation with the degree of medical-insurance-medicine linkage. Conclusions:Since the Sanming medical reform, the service security capacities in the fields of medical insurance, healthcare service, and pharmaceuticals, as well as the degree of medical-insurance-medicine linkage reform, have been continuously improved, showing the characteristics of differentiated development in different stages. Among them, medical insurance has played an engine role in the medical-insurance-medicine linkage reform of Sanming medical reform.

Objective To observe the value of MR intravoxel incoherent motion(IVIM)for analyzing placental microcirculation and microstructures in plateau area of late pregnancy induced hypertension(PIH)and normal middle and late pregnancy.Methods Totally 26 cases of PIH in late-trimester of pregnancy(group A)and 46 normal pregnant women(including 18 normal middle-trimester[group B]and 28 normal late-trimester[group C])in plateau area were retrospectively analyzed.The perfusion fraction(f),true diffusion coefficient(D)and pseudo-diffusion coefficient(D*)values of the entire placenta and the fetal side,maternal side and central region of placenta were obtained based on MR IVIM data,intra-and inter-group comparisons were conducted.Pearson correlation analysis was used to explore the relationships of placental IVIM parameters and maternal age,gestational age,estimated fetal weight(EFW)and neonatal birth weight.Results Except for f value of placental maternal side was higher than of fetal side in group C(P＜0.05),no significant difference was found in pairwise comparisons of IVIM parameters between different placental regions within each group(all P＞0.05).f value of the entire placenta and its fetal side,as well as D value of the entire placenta and its maternal side in group A were all higher than those in group C(all adjusted P＜0.05).The f and D* values of the entire placenta,f,D and D*values of its maternal side,as well as f and D* values of the fetal side in group C were all higher than those in group B(all adjusted P＜0.05).In group C,f value of placental maternal side was negatively correlated with both gestational age and EFW(r=-0.441,-0.579,both P＜0.01).Conclusion MR IVIM could be used to non-invasively assess placental microcirculation and microstructures in plateau area of late PIH and normal middle and late pregnancy women.

Objective In order to summarize the implementation status and effectiveness of entrusted management projects in municipal hospitals of Beijing,the project aims to better promote the extension of high-quality urban re-sources to county-level hospitals.Methods Through survey questionnaires and focus group interviews,the survey questionnaire includes the size of the hospital,the number of surgeries,Case Mix Index,annual average number of new technologies and projects,personnel training entrusted,and interviews with 50 heads of municipal hospi-tals,district hospitals,and district level government relevant departments.Results Measures for medical homogeni-zation,talent cultivation,management,and cultural homogenization were sorted out.In terms of hospital scale,level evaluation,medical service capabilities,and the proportion of master's degree and above personnel in the managed hospitals,an upward trend was observed.Conclusion The medical cooperation project entrusted by Beijing Municipal Hospitals promotes the integration of regional medical services,and provides reference for the expansion and sinking of high-quality medical resources from the management mechanism,operation mechanism and key measures.