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.

ObjectiveTo observe the analgesic efficacy and safety of Qihuang acupuncture theory combined with opioid analgesics in patients with moderate to severe cancer pain due to lung cancer. MethodsPatients with moderate to severe cancer pain from lung cancer were randomly divided into Qihuang acupuncture group and control group， with 33 cases in each group. The control group was treated with long-acting opioid analgesics at maintenance doses and supplementary analgesic medications as needed. In case of breakthrough pain， short-acting opioids were used for rescue. The Qihuang acupuncture group received Qihuang acupuncture treatment in addition to the treatment used in the control group， administered once every other day， with 3 sessions constituting one treatment course. The treatment duration for both groups was 5 days. The primary outcome was the change in pain intensity， measured using the numerical rating scale （NRS） before and after treatment， and the NRS change rate was calculated. Secondary endpoints included the daily NRS change rate， the Eastern Cooperative Oncology Group （ECOG） Performance Status （PS） score， the European Organization for Research and Treatment of Cancer Quality of Life Core Questionnaire （EORTC QLQ-C30） score， and the 24-hour equivalent hydrocodone sustained-release tablet dose. Laboratory tests， including routine blood， urine， stool， liver function， and kidney function， were performed before and after treatment. Adverse events were recorded throughout the trial. ResultsAll patients completed the trial， and both groups showed a decrease in average NRS scores and PS scores after treatment， with the Qihuang acupuncture group showing lower average NRS scores and PS scores than the control group （P＜0.05 or P＜0.01）. After treatment， the NRS change rate in the Qihuang acupuncture group was （0.42±0.17）， significantly higher than that in the control group （0.14±0.27， P＜0.01）. The daily NRS change rate during treatment was also higher in the Qihuang acupuncture group compared to the control group （P＜0.01）. The Qihuang acupuncture group showed an increase in overall health status and functional scores in the EORTC QLQ-C30， and a decrease in symptom scores for fatigue， nausea and vomiting， pain， dyspnea， insomnia， appetite loss， constipation， and financial difficulties. In contrast， overall health status and constipation scores in the control group increased， while scores of fatigue， nausea and vomiting， pain， and appetite loss decreased （P＜0.05 or P＜0.01）. After treatment， the 24-hour equivalent hydrocodone sustained-release tablet dose did not show significant difference in the Qihuang acupuncture group （P＞0.05）， while the control group showed a significant increase in the 24-hour dose （P＜0.01）. No significant abnormalities were observed in laboratory tests before and after treatment in either group. During the study， the incidence of nausea and vomiting as well as constipation in the Qihuang acupuncture group was both 3.03% （1/33）， while the incidence in the control group was 27.27% （9/33） and 36.36% （12/33）， respectively， with the Qihuang acupuncture group showing significantly lower incidence （P＜0.01）. No serious adverse reactions were observed in either group. ConclusionQihuang acupuncture therapy combined with opioid analgesics is more effective than using opioids alone in relieving pain in patients with moderate to severe cancer pain due to lung cancer. It can improve the patients' physical condition and quality of life， reduce the dose of opioid analgesics， and has good safety.

As a mercury-containing elixir， Hongshengdan has been known as a sacred medicine for surgery by ancient medical practitioners because of its precise curative effects. It originated from Yizong Shuoyue in the Qing dynasty， Qing dynasty and modern medical practitioners have adapted and modified its formula for clinical application. Employing bibliometric methods， the authors systematically organized relevant ancient literature of the Qing dynasty and modern literature， and analyzed the composition and dosage， preparation method， and clinical application. Among the 25 ancient books concerning Hongshengdan， a total of 12 medicinal formulas， 15 refining methods and 9 clinical applications were obtained. Research confirms that Hongshengdan consisted of mercury， saltpeter， alum， soap alum， cinnabar and realgar. Using measurement conversion standards of Qing dynasty， the modern single-batch formulation comprised 37.30 g of mercury， 149.20 g of saltpeter， 37.30 g of alum， 22.38 g of soap alum， 18.65 g of cinnabar， and 18.65 g of realgar. In modern refining of Hongshengdan， most medical practitioners take the core medicines， with dosages approximately 30 g of mercury， 30 g of saltpeter， and 30 g of alum. Refining method involves pretreatment stewing the materials during preparation， and alum， soap alum， and saltpeter are first ground together， then combined with mercury， cinnabar， and realgar for grinding until mercury and other drugs grind to the degree of no star points. The mixture is then placed in a pot or vessel by cold-forming method. After covering， the opening is sealed using either raw gypsum salt mud or honey-dipped cotton paper strips. Sand is packed around the vessel and then pressurized. During the calcination process， begin with a low flame（30 min）， then increase to a medium flame（30 min）， followed by a high flame（30 min）， after removing fire toxins， collect the final product. Hongshengdan has the efficacy of lifting the poison， removing the corrosion， producing muscle and dispersing， and is often used in the treatment of surgical sore and carbuncle type of diseases. Modern research indicates that Hongshengdan is commonly used to treat skin system diseases such as ulcers and herpes. The aforementioned findings provide a reference basis for the subsequent refining method and clinical application of Hongshengdan.

Background: Reconstruction of mandibular and maxillary defects resulting from malignant tumors has remained a complex challenge in recent years. Defects caused by tumors—as well as trauma, inflammatory diseases, and congenital anomalies—lead to impaired essential functions such as mastication, swallowing, and speech. Prior to the 1950s, reconstruction of maxillofacial hard tissue was not commonly performed. Instead, metal plates were used to reestablish bony continuity, and surrounding tissues were utilized to close soft tissue defects, without effectively restoring function. With modern advances in three-dimensional (3D) virtual planning, it is now possible to accurately plan free bone flaps for reconstructing jaw defects. During surgery, manually bending reconstruction plates to fit donor bone precisely is often not feasible. Preoperative 3D planning allows for precise fabrication of surgical guides and fixation plates, improving accuracy and significantly reducing operative time. Additionally, incorporating dental implant planning into the reconstruction process facilitates restoration of both structural and functional outcomes. Aim: To evaluate the outcomes of mandibular defect reconstruction using scapular free flaps in Mongolia and explore potential approaches to optimize the technique. Materials and Methods: This was a case study series. Data from reconstructive surgeries performed at the National Cancer Center of Mongolia, Central Dental Hospital, and the Mongolia-Japan Hospital were collected. Variables included patient age and sex, etiology of the mandibular defect, size of the scapular bone segment, operative time, ischemia time of the free flap, number of vascular anastomoses performed, and pedicle length. For 3D planning, CT scans of the patient's head and lower limb (slice thickness <1 cm) were used to generate 3D models via the 3D Slicer software. Cutting guides for the mandible and scapula (ASIGA), as well as the reconstruction models (AMS), were printed using a 3D printer. Results: A total of 400 free flap reconstructions were performed during the study period. Of these, 29 cases involved reconstruction of mandibular defects using scapular free flaps. The mean age of patients was 40.0 ± 18.3 years, with 52% (15 patients) being female. The etiologies of the defects included malignant tumors (13 cases, 45%), benign tumors (6 cases, 21%), and pre-existing defects (10 cases, 34%). In one case, tumor resection and mandibular reconstruction were performed using 3D planning. The total operative time was 9 hours and 30 minutes, and the ischemia time was 2 hours and 40 minutes. Conclusion Between 2012 and 2025, a total of 29 mandibular reconstructions using scapular free flaps were performed in Mongolia. Traditional reconstruction methods were associated with prolonged ischemia time. The use of 3D surgical planning has shown potential in significantly reducing ischemia time and improving surgical outcomes.

PURPOSE: The rate of complications among patients undergoing surgery has increased due to infection with SARS-CoV-2 and other variants of concern. However, Omicron has shown decreased pathogenicity, raising questions about the risk of postoperative complications among patients who are infected with this variant. This study aimed to investigate complications and related factors among patients with recent Omicron infection prior to undergoing orthopedic surgery. METHODS: A historical control study was conducted. Data were collected from all patients who underwent surgery during 2 distinct periods: (1) between Dec 12, 2022 and Jan 31, 2023 (COVID-19 positive group), (2) between Dec 12, 2021 and Jan 31, 2022 (COVID-19 negative control group). The patients were at least 18 years old. Patients who received conservative treatment after admission or had high-risk diseases or special circumstances (use of anticoagulants before surgery) were excluded from the study. The study outcomes were the total complication rate and related factors. Binary logistic regression analysis was used to identify related factors, and odds ratio (OR) and 95% confidence interval (CI) were calculated to assess the impact of COVID-19 infection on complications. RESULTS: In the analysis, a total of 847 patients who underwent surgery were included, with 275 of these patients testing positive for COVID-19 and 572 testing negative. The COVID-19-positive group had a significantly higher rate of total complications (11.27%) than the control group (4.90%, p < 0.001). After adjusting for relevant factors, the OR was 3.08 (95% CI: 1.45-6.53). Patients who were diagnosed with COVID-19 at 3-4 weeks (OR = 0.20 (95% CI: 0.06-0.59), p = 0.005), 5-6 weeks (OR = 0.16 (95% CI: 0.04-0.59), p = 0.010), or ≥7 weeks (OR = 0.26 (95% CI: 0.06-1.02), p = 0.069) prior to surgery had a lower risk of complications than those who were diagnosed at 0-2 weeks prior to surgery. Seven factors (age, indications for surgery, time of operation, time of COVID-19 diagnosis prior to surgery, C-reactive protein levels, alanine transaminase levels, and aspartate aminotransferase levels) were found to be associated with complications; thus, these factors were used to create a nomogram. CONCLUSION Omicron continues to be a significant factor in the incidence of postoperative complications among patients undergoing orthopedic surgery. By identifying the factors associated with these complications, we can determine the optimal surgical timing, provide more accurate prognostic information, and offer appropriate consultation for orthopedic surgery patients who have been infected with Omicron.
Humans ; COVID-19/complications* ; Male ; Female ; Middle Aged ; Postoperative Complications/epidemiology* ; SARS-CoV-2 ; Orthopedic Procedures/adverse effects* ; Aged ; Nomograms ; Adult ; Retrospective Studies ; Risk Factors

[This corrects the article DOI: 10.1016/j.apsb.2022.03.002.].

[This corrects the article DOI: 10.1016/j.apsb.2021.07.024.].

Receptor-interacting protein kinase 1 (RIPK1) plays an essential role in regulating the necroptosis and apoptosis in cerebral ischemia-reperfusion (I/R) injury. However, the regulation of RIPK1 kinase activity after cerebral I/R injury remains largely unknown. In this study, we found the downregulation of protein arginine methyltransferase 1 (PRMT1) was induced by cerebral I/R injury, which negatively correlated with the activation of RIPK1. Mechanistically, we proved that PRMT1 directly interacted with RIPK1 and catalyzed its asymmetric dimethylarginine, which then blocked RIPK1 homodimerization and suppressed its kinase activity. Moreover, pharmacological inhibition or genetic ablation of PRMT1 aggravated I/R injury by promoting RIPK1-mediated necroptosis and apoptosis, while PRMT1 overexpression protected against I/R injury by suppressing RIPK1 activation. Our findings revealed the molecular regulation of RIPK1 activation and demonstrated PRMT1 would be a potential therapeutic target for the treatment of ischemic stroke.

Temporomandibular joint (TMJ) disc displacement is one of the most significant subtypes of temporomandibular joint disorders, but its etiology and mechanism are poorly understood. In this study, we elucidated the mechanisms by which destruction of inflamed collagen fibrils induces alterations in the mechanical properties and positioning of the TMJ disc. By constructing a rat model of TMJ arthritis, we observed anteriorly dislocated TMJ discs with aggravated deformity in vivo from five weeks to six months after a local injection of Freund's complete adjuvant. By mimicking inflammatory conditions with interleukin-1 beta in vitro, we observed enhanced expression of collagen-synthesis markers in primary TMJ disc cells cultured in a conventional two-dimensional environment. In contrast, three-dimensional (3D)-cultivated disc cell sheets demonstrated the disordered assembly of inflamed collagen fibrils, inappropriate arrangement, and decreased Young's modulus. Mechanistically, inflammation-related activation of the nuclear factor kappa-B (NF-κB) pathway occurs during the progression of TMJ arthritis. NF-κB inhibition reduced the collagen fibril destruction in the inflamed disc cell sheets in vitro, and early NF-κB blockade alleviated collagen degeneration and dislocation of the TMJ discs in vivo. Therefore, the NF-κB pathway participates in the collagen remodeling in inflamed TMJ discs, offering a potential therapeutic target for disc displacement.
Animals ; NF-kappa B/metabolism* ; Temporomandibular Joint Disorders/pathology* ; Temporomandibular Joint Disc/metabolism* ; Rats ; Rats, Sprague-Dawley ; Disease Models, Animal ; Male ; Collagen/metabolism* ; Cells, Cultured ; Joint Dislocations/pathology* ; Interleukin-1beta ; Arthritis, Experimental