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.

ObjectiveTo compare the differences in color， odor， coumarin content and microbial community composition of Angelicae Dahuricae Radix（ADR） during different drying processes， and to explore the correlation between changes in microbial community composition and changes in quality indexes of ADR. MethodsThe fresh ADR was processed at three drying temperatures（50， 70， 100 ℃） by drying and steaming cutting， semi-fresh cutting and drying， fresh cutting and drying， and sulfur fumigation methods. The color values of samples were extracted by Adobe Photoshop 2022 software and subjected to principal component analysis（PCA）， electronic nose was used to identify the odor information of medicinal powders and subjected to loadings analysis， PCA， and linear discriminant analysis（LDA）， and high performance liquid chromatography（HPLC） was used to determine the contents of five coumarins（bergapten， oxypeucedanin， imperatorin， phellopterin， isoimperatorin）. The samples for microbial detection were taken from fresh dried samples， 50 ℃（dried and steamed cut， sulfur fumigated） samples， and 100 ℃（dried and steamed cut） samples when the water content was 50% and 14%， respectively. And the changes of microbial community composition during processing were determined by high-throughput sequencing method. The relationship between the changes of microbial community composition and the changes of odor， color and active component content of ADR during drying process was analyzed by Pearson correlation analysis. ResultsThe color quantification results showed that an increase in drying temperature led to the decrease of brightness value（L）， and the increases of red-green value（a） and yellow-blue value（b）， and the change of processing method had no obvious effect on the color of medicinal materials. The results of odor quantification showed that W1S， W2S， W5S， W2W and W1W sensor were sensitive to the odor changes of ADR and could be used to distinguish ADR decoction pieces from different processing methods. The results of HPLC showed that the coumarin content of ADR decreased with the increase of drying temperature and the delay of processing time， the optimal processing method was drying and steaming cutting method， and the optimal temperature was 50 ℃. High-throughput sequencing results showed that the dominant bacteria in ADR during processing were Achromobacter， Agrobacterium， Nocardioides， Mycobacterium and Enterobacter， the dominant fungi were Coprinopsis， Meyerozyma and Apiotrichum. The results of correlation analysis showed that the quality indexes of ADR were positively correlated with Agrobacterium， Mycobacterium in bacteria， Candida in fungi， and negatively correlated with Bacillus in bacteria. ConclusionThere are significant differences in the color， odor， coumarin content and microbial community composition of ADR in different drying processes， and the best drying method is drying and steaming cutting at 50 ℃. The relative abundance changes of 9 bacterial genera and 4 fungal genera are closely related to the quality formation of ADR during the drying process.

This study aims to investigate the anti-inflammatory and anti-apoptotic effects of total flavonoids of hawthorn leaves(TFHL)on lipopolysaccharide(LPS)-induced inflammatory injury in rat intestinal epithelial(IEC-6)cells,as well as the underlying mechanisms.An in vitro inflam-mation model was first established by treating IEC-6 cells with lipopolysaccharide(LPS).IEC-6 cells were then incubated with three concentrations of TFHL for 24 h prior to a further 24 h LPS treatment.RT-qPCR was used to quantify mRNA levels of the inflammatory genes COX-2 and iN-OS,while Western blotting was used to assess protein levels of the apoptotic markers Bax,cleaved Caspase-3,Bcl-2,and the JNK/p-JNK signaling pathway.Finally,cells were pretreated with TFHL and/or the JNK inhibitor SP600125 for 24 h before LPS exposure for 24 h,in order to evaluate the combined effects of TFHL and SP600125 on LPS-induced inflammatory cytokine expression and apoptotic protein levels in IEC-6 cells.The results showed that,compared with the LPS group,the mRNA level of COX-2 and iNOS in the 2.5,5.0,10.0 mg/L TFHL group and the Bax and Caspase-3 protein levels decreased significantly(P＜0.01),and the Bcl-2 protein level was significantly higher(P＜0.01),p-JNK protein level and p-JNK/JNK ratio decreased significantly(P＜0.01);compared with the LPS group,the COX-2 and iNOS mRNA levels of the TFHL+LPS group de-creased significantly(P＜0.01),Bax,and Caspase-3 protein levels decreased significantly(P＜0.01),and the level of Bcl-2 protein increased significantly(P＜0.05);compared with the LPS group,the COX-2 and iNOS mRNA levels of the TFHL+SP600125 group decreased significantly(P＜0.01),Bax and Caspase-3 protein levels decreased significantly(P＜0.01),and Bcl-2 protein level increased significantly(P＜0.01).These findings indicate that TFHL exerts anti-inflammato-ry and anti-apoptotic effects in LPS-challenged IEC-6 cells by inhibiting the JNK signaling path-way.

Hyperemesis gravidarum(HG)refers to persistent and severe nausea and vomiting during early pregnancy.Severe HG may lead to maternal dehydration,electrolyte imbalances,malnutrition,and even hypotension and arrhythmias,potentially affecting fetal growth and development.Due to the unique physiological state of pregnancy,treatment options for HG are limited.Metoclopramide,has become a commonly used drug in treating HG due to its prove efficacy and safety.Previous studies have primarily focused on the extrapyramidal side effects of metoclopramide,but research on its psychiatric adverse effects,such as mania and somnolence,remains limited,particularly in pregnant patients.This paper reports a case of psychiatric abnormalities in an HG patient following metoclopramide administration.By analyzing the patient's condition,medication use,and adverse reactions,this study explores the potential mechanisms underlying metoclopramide-induced psychiatric abnormalities and provides clinical recommendations for preventing and managing such psychiatric adverse effects during pregnancy.These findings offer valuable guidance for healthcare professionals regarding the appropriate use of this medication.

Objective:To investigate the epidemiological and clinical characteristics of patients with psittacosis, in order to provide a basis for early diagnosis and prevention of the disease.Methods:Clinical data of psittacosis cases reported in 2023 from China Disease Prevention and Control Information System in Daxing District, Beijing were collected, and the patients' general information, epidemiological characteristics, clinical characteristics, imaging examination results, laboratory test results, treatment and prognosis were retrospectively analyzed.Results:A total of 7 cases of psittacosis were reported in Daxing District in 2023, with no clustered infection in households or workplaces. There were 4 males and 3 females, with a median age of 66 years old, and a range of 52 to 82 years old. Epidemiological investigation revealed that 6 patients had a clear history of contact with poultry (4 had first contact with parrots or pigeons, and 2 had long-term exposure to pigeons, parrots or wild birds). The onset time was concentrated in April and May. The primary clinical manifestations included high fever (6 cases), fatigue (4 cases), and chills (3 cases). The imaging examination results showed that inflammatory changes occurred in the unilateral lung of 6 patients, and both lungs were affected in 1 patients. Laboratory test results indicated elevated neutrophill percentage in 6 patients, decreased white blood cell counts in 2 patients, elevated white blood cell counts in 2 patients, and elevated C-reactive protein levels in 7 patients. Metagenomic next-generation sequencing test showed that all seven patients were positive for Chlamydia psittaci. All 7 patients were treated with quinolone or tetracycline antibiotics, with 6 cured and discharged, and 1 died. Conclusion:Psittacosis is usually manifested clinically as high fever, fatigue, and unilateral lung inflammation, often associated with poultry exposure.

Various researches have reported on the relationship between homocysteine levels and adverse pregnancy outcomes. Researchers are increasingly focusing on the impact of homocysteine on female reproductive health and figuring out the potential positive effects of lowering homocysteine levels on women fertility. Our review aims to systematically summarize the possible roles of homocysteine in female reproductive disorders based on relevant studies from the past 15 years and therapeutic prospects targeting homocysteine to improve the reproductive health of women.

Objective:To evaluate the cumulative live birth rate (CLBR) and cost-effectiveness of fixed versus adjusted follicle-stimulation hormone (FSH) dosages in infertile women with different ovarian responses during their first assisted reproductive technology (ART) cycle.Methods:A retrospective real-world cohort study was conducted on 5 419 infertile women who underwent their first ART treatment at the Department of Reproductive Medicine of the First Affiliated Hospital of Nanjing Medical University between January 2013 and December 2017. All patients received an individualized starting dosage of gonadotropin. Based on whether FSH dosages were adjusted during controlled ovarian stimulation (COS), patients were divided into fixed-dosage group ( n=2 061) and adjusted-dosage group ( n=3 358). Clinical outcomes and FSH cost-effectiveness were compared between the two groups across different ovarian response groups, with CLBR as the primary outcome. Propensity score matching (PSM) and multivariable logistic regression were used to adjust for potential confounders. Results:FSH dosage adjustments were found in 62.0% (3 358/5 419) of cycles during COS. After PSM, baseline characteristics were comparable between the two groups (all P>0.05). After adjusting for confounders using multivariable logistic regression, FSH dosage adjustment was not significantly associated with CLBR ( OR=1.06, 95% CI: 0.94-1.20, P=0.332). Compared with the adjusted-dosage group, the fixed-dosage group showed no significant differences in CLBR in poor-, normal-, and high-responder groups (all P>0.05). The incidence of ovarian hyperstimulation syndrome (OHSS) did not differ significantly between the two groups ( P>0.05). In poor-, normal-, and high-responder groups, the total FSH dosages in the fixed-dose group [1 350 (375, 1 825) U, 1 200 (375, 1 500) U and 525 (375, 1 128) U, respectively] were significantly lower than those in the adjusted-dose group [1 875 (1 425, 2 294) U, P=0.001; 1 425 (450, 1 875) U, P<0.001; 600 (375, 1 425) U, P=0.020]. Similarly, average FSH costs in different ovarian response groups in the fixed-dosage group [4 725.0 (1 312.5, 6 387.5) yuan, 4 200.0 (1 312.5, 5 250.0) yuan and 1 837.5 (1 312.5, 3 947.3) yuan, respectively] were significantly lower than those in the adjusted-dosage group [6 562.5 (4 987.5, 8 028.1) yuan, P=0.001; 4 987.5 (1 575.0, 6 562.5) yuan, P<0.001; 2 100.0 (1 312.5, 4 987.5) yuan, P=0.020]. For normal-responders, the FSH cost per high-quality embryo in the fixed-dosage group [1 365.0 (875.0, 2 537.5) yuan] was significantly lower than that in the adjusted-dosage group [2 056.3 (1 268.8, 3 412.5) yuan, P<0.001]. Conclusion:FSH dosage adjustment during COS is not associated with CLBR or the incidence of OHSS. However, the fixed-dose group exhibited lower total FSH dosages and costs across different ovarian response populations. In the context of ART being covered by medical insurance, fixed FSH dosage may represent a more cost-effective ovarian stimulation protocol.

The scientific research and innovation capabilities of medical students are intrinsically linked to the sustained and high-quality development of national healthcare initiatives.Cultivating outstanding medi-cal students with independent scientific capabilities and innovative consciousness is a critical component in the education and training of high-level medical professionals.Our investigation revealed that within the imperfections of the cultivating model,some faculty and students at medical schools have an insufficient understanding of scientific research and innovation and lack motivation for engaging in such activities,which hinder the progression of scientific research activities.Consequently,we initiated a teaching practice and exploratory study on the"tutorial system"aimed at fostering medical students'scientific research and innovation abilities.Based on the principle of"research informing teaching,teaching and research advan-cing together,"this study implements a"tutorial system"coordinated by tutors,supplemented by graduate and undergraduate student mentors,to cultivate innovative thinking,stimulate interest in scientific re-search,and enhance practical and research skills among medical students.Through collaborative efforts within"scientific research innovation teams,"various educational methods—including preliminary re-search,in-class and extracurricular activities,intra-group and inter-group interactions,and theoretical and practical applications—are employed to improve and strengthen the cultivation of medical students'scientif-ic research and innovation abilities.This study aims to provide valuable references for optimizing medical education management systems and enhancing the quality of medical student training.