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 study effective methods for reducing lung V₅, V₁₀, and mean lung dose (MLD) in the design of volumetric modulated arc therapy for central lung cancer by using different arc configurations and dose-limiting blocks designs. METHODS: Five groups of plans were designed for the enrolled patients. Group A used a full-arc field. Group B used a partial-arc field. Groups C, D, and E used full-arc fields with vertical-length, semi-ring, and triangular dose-limiting blocks added respectively. The dosimetric similarities of target areas and the dosimetric differences in lung V₅, V₁₀, V₂₀, and MLD among the groups were compared. RESULTS: Compared with group A, groups B, C, D, and E had decreased homogeneity and conformity of the target area, but significantly lower V₅ and V₁₀ of the whole lung. The MLD of groups C, D, and E was lower than that of group A. CONCLUSION Using a full-arc field combined with dose-limiting blocks can effectively reduce lung V₅, V₁₀, MLD, and monitor units (MU).
Lung Neoplasms/radiotherapy* ; Humans ; Radiotherapy, Intensity-Modulated/methods* ; Radiotherapy Planning, Computer-Assisted/methods* ; Radiotherapy Dosage ; Lung/radiation effects*

OBJECTIVE To investigate the improvement mechanism of Huatan tongmai decoction on rats with polycystic ovary syndrome （PCOS） by regulating autophagy through phosphatidylinositol-3-kinase（PI3K）/protein kinase B（AKT）/mammalian target of rapamycin （mTOR） pathway. METHODS A total of 40 rats were randomly divided into blank group （purified water）， model group （purified water）， traditional Chinese medicine group [Huatan tongmai decoction， 24 g/（kg·d）] and chemical drug group [metformin， 0.16 g/（kg·d）]， with 10 rats in each group. Except for blank group， other groups were given a combination of high-fat diet and intragastric administration of 1 mg/kg letrozole suspension to establish PCOS rat model. After modeling， they were given relevant medicine or water intragastrically， once a day， for 42 consecutive days. After the last administration， the pathological and ultrastructural changes of ovarian tissue were observed. The levels of follicle stimulating hormone （FSH）， testosterone （T）， estradiol （E2） ，luteinizing hormone （LH） in serum were detected，and the LH/FSH ratio was calculated. mRNA expressions of Beclin-1， p62 and microtubule-associated protein 1 light chain 3 （LC3） in ovarian tissue were detected. The expressions of related proteins of PI3K/AKT/mTOR pathway and autophagy in rat ovarian tissues were also detected. RESULTS Compared with blank group， the pathological damage and ultrastructural changes of the ovarian tissue in the model group rats were obvious， and a large number of autophagosomes could be seen in cells. The levels of T and LH and the LH/FSH ratio in serum， as well as mRNA and protein expressions of Beclin-1 and LC3， were increased significantly （P＜0.05）， while the levels of E2 and FSH in serum， as well as mRNA and protein expressions of p62 and the phosphorylation levels of PI3K， AKT and mTOR proteins in ovarian tissue， were significantly decreased （P＜0.05）. Compared with model group， the pathological damage of ovarian tissue in the administration groups was significantly reduced， the number of autophagosomes was smaller， and the expression levels of the above indicators were significantly reversed （P＜0.05）. CONCLUSIONS Huatan tongmai decoction can inhibit autophagy in ovarian granular cells by activating the PI3K/AKT/mTOR pathway， regulate the secretion of sex hormones， alleviate pathological damage in ovarian tissues， and promote normal follicular development， thereby exerting an ameliorative effect on PCOS rats.

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

Two novel diketopiperazines (1 and 5), along with ten known compounds (2-4, 6-12) demonstrating significant skin inflammation inhibition, were isolated from a marine-derived fungus identified as Aspergillus sp. FAZW0001. The structural elucidation and configurational reassessments of compounds 1-5 were established through comprehensive spectral analyses, with their absolute configurations determined via single crystal X-ray diffraction using Cu Kα radiation, Marfey's method, and comparison between experimental and calculated electronic circular dichroism (ECD) spectra. Compounds 1, 2, and 8 exhibited significant anti-inflammatory activities in Propionibacterium acnes (P. acnes)-induced human monocyte cell lines. Compound 8 demonstrated the ability to down-regulate interleukin-1β (IL-1β) expression by inhibiting Toll-like receptor 2 (TLR2) expression and modulating the activation of myeloid differentiation factor 88 (MyD88), mitogen-activated protein kinase (MAPK), and nuclear factor κB (NF-κB) signaling pathways, thus reducing the cellular inflammatory response induced by P. acnes. Additionally, compound 8 showed the capacity to suppress mitochondrial reactive oxygen species (ROS) production and nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome activation, thereby reducing IL-1β maturation and secretion. A three-dimensional quantitative structure-activity relationships (3D-QSAR) model was applied to compounds 5-12 to analyze their anti-inflammatory structure-activity relationships.
Humans ; Aspergillus/chemistry* ; Diketopiperazines/isolation & purification* ; Anti-Inflammatory Agents/isolation & purification* ; Interleukin-1beta/genetics* ; Toll-Like Receptor 2/immunology* ; Propionibacterium acnes/drug effects* ; NF-kappa B/genetics* ; Molecular Structure ; Myeloid Differentiation Factor 88/immunology* ; Monocytes/immunology* ; NLR Family, Pyrin Domain-Containing 3 Protein/genetics* ; Cell Line

Hongsheng Dan, historically referred to as the "surgical sacred medicine", is at risk of losing its refining technology in contemporary times. This study aimed to preserve and innovate this traditional non-heritage refining technology. By utilizing the analytic hierarchy process(AHP) combined with the entropy weight method, this study established the hierarchical structure model of refining process of Hongsheng Dan and conducted a single factor experiment and an L_9(3~4) orthogonal experiment to optimize the refining method of Hongsheng Dan. Additionally, the study employed infrared thermal imaging to monitor temperature variations of Hongsheng Dan during the refining process. The optimized refining parameters for Hongsheng Dan were established as follows: a slow fire temperature of 175 ℃ with a duration of 30 minutes, a strong fire temperature of 270 ℃ with a duration of 60 minutes, and a tail fire temperature of 180 ℃ with a duration of 15 minutes. The stability and feasibility of this optimized process were confirmed through validation tests. The research focused on the material transformation of Hongsheng Dan, starting from the material changes during the refining process of Hongsheng Dan and the synthesis of mercuric oxide from nitric acid. The study investigated elemental transformations, physical phase changes, and alterations in thermal properties. 78.98% of the mercury in Hongsheng Dan and 80.21% of the mercury in mercuric oxide from nitric acid were retained. The diffraction peak intensity of the(011) crystal plane of Hongsheng Dan was highest at approximately 30.07°, indicating that the(011) crystal plane had a preferred crystalline orientation. Furthermore, the temperature range for the alteration in thermal properties during the refining process of Hongsheng Dan was found to be between 80 ℃ and 130 ℃. This research not only optimized the refining technology of Hongsheng Dan but also pioneered the application of infrared thermal imaging to study temperature changes throughout the refining process. By exploring the material transformation patterns of Hongsheng Dan and the synthesis of mercuric oxide from nitric acid, the study provided technical support for the preservation and innovation of Hongsheng Dan.
Drugs, Chinese Herbal/standards* ; Temperature

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 an evidence-based practice program of discharge preparation services for hip replacement patients based on the best evidence,and to evaluate its clinical effects,aiming to provide references for the implementation of relevant interventions.Methods Knowledge to Action Framework was used as a guide to summarise the best evidence on discharge preparation services for hip replacement patients and to select services based on clinical context.We selected 38 hip replacement patients and 17 healthcare professionals from the De-partment of Orthopaedic Surgery at a tertiary A hospital in Shanghai in September-October 2023 to conduct a baseline review,identify facilitating and hindering factors,and develop a practice protocol.We also selected 38 hip replacement patients and 17 healthcare professionals from November-December 2023 on this ward for evidence-based practice.Nurses'rates of completion of review indicators,levels of knowledge of discharge preparation ser-vices,and discharge planning competencies were compared before and after practice.Patients'readiness for dis-charge,hip function,and unplanned readmissions were also compared before and after the practice.Results After evidence-based practice,nurses'completion rates of review indicators,knowledge of discharge preparation services,and discharge planning competencies were higher than baseline levels(P＜0.05).Hip replacement patients showed a significant improvement in readiness for discharge and hip function(P＜0.001).Conclusion The implementation of an evidence-based practice program of discharge preparation services improves nurses'knowledge and skills,and also contributes to the discharge readiness and hip function of hip replacement patients.

Lung cancer is one of the malignant tumours with the highest morbidity and mortality rates worldwide today, posing a major threat to human health. Accurate diagnosis and standardised treatment play a crucial role in improving the survival rate of lung cancer patients. In recent years, the rapid rise of artificial intelligence (AI) has brought about significant changes in the medical field, providing a new diagnostic and treatment model for lung cancer, and making a series of breakthroughs in lung cancer diagnostic imaging, pathological diagnosis, surgical oncology, radiotherapy, and drug development and treatment. This article introduces the current status of AI application in the field of lung cancer diagnosis and treatment, and extensively discusses the current challenges and future prospects, hoping to provide references and suggestions for future clinical practice.

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.