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 therapeutic effects and underlying mechanisms of Dendrobium officinale (Tiepi Shihu) extract (DOE) on insomnia. METHODS: Forty-two male Sprague-Dawley rats were randomly divided into 6 groups (n=7 per group): normal control, model control, melatonin (MT, 40 mg/kg), and 3-dose DOE (0.25, 0.50, and 1.00 g/kg) groups. Rats were raised in a strong-light (10,000 LUX) and -noise (>80 db) environment (12 h/d) for 16 weeks to induce insomnia, and from week 10 to week 16, MT and DOE were correspondingly administered to rats. The behavior tests including sodium pentobarbital-induced sleep experiment, sucrose preference test, and autonomous activity test were used to evaluate changes in sleep and emotions of rats. The metabolic-related indicators such as blood pressure, blood viscosity, blood glucose, and uric acid in rats were measured. The pathological changes in the cornu ammonis 1 (CA1) region of rat brain were evaluated using hematoxylin and eosin staining and Nissl staining. Additionally, the sleep-related factors gamma-aminobutyric acid (GABA), glutamate (GA), 5-hydroxytryptamine (5-HT), and interleukin-6 (IL-6) were measured using enzyme linked immunosorbent assay. Finally, we screened potential sleep-improving receptors of DOE using polymerase chain reaction (PCR) array and validated the results with quantitative PCR and immunohistochemistry. RESULTS: DOE significantly improved rats' sleep and mood, increased the sodium pentobarbital-induced sleep time and sucrose preference index, and reduced autonomic activity times (P<0.05 or P<0.01). DOE also had a good effect on metabolic abnormalities, significantly reducing triglyceride, blood glucose, blood pressure, and blood viscosity indicators (P<0.05 or P<0.01). DOE significantly increased the GABA content in hippocampus and reduced the GA/GABA ratio and IL-6 level (P<0.05 or P<0.01). In addition, DOE improved the pathological changes such as the disorder of cell arrangement in the hippocampus and the decrease of Nissel bodies. Seven differential genes were screened by PCR array, and the GABA_A receptors (Gabra5, Gabra6, Gabrq) were selected for verification. The results showed that DOE could up-regulate their expressions (P<0.05 or P<0.01). CONCLUSION DOE demonstrated remarkable potential for improving insomnia, which may be through regulating GABA_A receptors expressions and GA/GABA ratio.
Animals ; Dendrobium/chemistry* ; Rats, Sprague-Dawley ; Male ; Sleep Initiation and Maintenance Disorders/blood* ; Plant Extracts/therapeutic use* ; Receptors, GABA-A/metabolism* ; Noise/adverse effects* ; Light/adverse effects* ; gamma-Aminobutyric Acid/metabolism* ; Sleep/drug effects* ; Rats ; Receptors, GABA/metabolism*

Apical microsurgery is accurate and minimally invasive, produces few complications, and has a success rate of more than 90%. However, due to the lack of awareness and understanding of apical microsurgery by dental general practitioners and even endodontists, many clinical problems remain to be overcome. The consensus has gathered well-known domestic experts to hold a series of special discussions and reached the consensus. This document specifies the indications, contraindications, preoperative preparations, operational procedures, complication prevention measures, and efficacy evaluation of apical microsurgery and is applicable to dentists who perform apical microsurgery after systematic training.
Microsurgery/standards* ; Humans ; Apicoectomy ; Contraindications, Procedure ; Tooth Apex/diagnostic imaging* ; Postoperative Complications/prevention & control* ; Consensus ; Treatment Outcome

Pulpotomy, which belongs to vital pulp therapy, has become a strategy for managing pulpitis in recent decades. This minimally invasive treatment reflects the recognition of preserving healthy dental pulp and optimizing long-term patient-centered outcomes. Pulpotomy is categorized into partial pulpotomy (PP), the removal of a partial segment of the coronal pulp tissue, and full pulpotomy (FP), the removal of whole coronal pulp, which is followed by applying the biomaterials onto the remaining pulp tissue and ultimately restoring the tooth. Procedural decisions for the amount of pulp tissue removal or retention depend on the diagnostic of pulp vitality, the overall treatment plan, the patient's general health status, and pulp inflammation reassessment during operation. This statement represents the consensus of an expert committee convened by the Society of Cariology and Endodontics, Chinese Stomatological Association. It addresses the current evidence to support the application of pulpotomy as a potential alternative to root canal treatment (RCT) on mature permanent teeth with pulpitis from a biological basis, the development of capping biomaterial, and the diagnostic considerations to evidence-based medicine. This expert statement intends to provide a clinical protocol of pulpotomy, which facilitates practitioners in choosing the optimal procedure and increasing their confidence in this rapidly evolving field.
Humans ; Calcium Compounds/therapeutic use* ; Consensus ; Dental Pulp ; Dentition, Permanent ; Oxides/therapeutic use* ; Pulpitis/therapy* ; Pulpotomy/standards*

Intentional tooth replantation (ITR) is an advanced treatment modality and the procedure of last resort for preserving teeth with inaccessible endodontic or resorptive lesions. ITR is defined as the deliberate extraction of a tooth; evaluation of the root surface, endodontic manipulation, and repair; and placement of the tooth back into its original socket. Case reports, case series, cohort studies, and randomized controlled trials have demonstrated the efficacy of ITR in the retention of natural teeth that are untreatable or difficult to manage with root canal treatment or endodontic microsurgery. However, variations in clinical protocols for ITR exist due to the empirical nature of the original protocols and rapid advancements in the field of oral biology and dental materials. This heterogeneity in protocols may cause confusion among dental practitioners; therefore, guidelines and considerations for ITR should be explicated. This expert consensus discusses the biological foundation of ITR, the available clinical protocols and current status of ITR in treating teeth with refractory apical periodontitis or anatomical aberration, and the main complications of this treatment, aiming to refine the clinical management of ITR in accordance with the progress of basic research and clinical studies; the findings suggest that ITR may become a more consistent evidence-based option in dental treatment.
Humans ; Tooth Replantation/methods* ; Consensus ; Periapical Periodontitis/surgery*

Cemental tear is a rare and indetectable condition unless obvious clinical signs present with the involvement of surrounding periodontal and periapical tissues. Due to its clinical manifestations similar to common dental issues, such as vertical root fracture, primary endodontic diseases, and periodontal diseases, as well as the low awareness of cemental tear for clinicians, misdiagnosis often occurs. The critical principle for cemental tear treatment is to remove torn fragments, and overlooking fragments leads to futile therapy, which could deteriorate the conditions of the affected teeth. Therefore, accurate diagnosis and subsequent appropriate interventions are vital for managing cemental tear. Novel diagnostic tools, including cone-beam computed tomography (CBCT), microscopes, and enamel matrix derivatives, have improved early detection and management, enhancing tooth retention. The implementation of standardized diagnostic criteria and treatment protocols, combined with improved clinical awareness among dental professionals, serves to mitigate risks of diagnostic errors and suboptimal therapeutic interventions. This expert consensus reviewed the epidemiology, pathogenesis, potential predisposing factors, clinical manifestations, diagnosis, differential diagnosis, treatment, and prognosis of cemental tear, aiming to provide a clinical guideline and facilitate clinicians to have a better understanding of cemental tear.
Humans ; Dental Cementum/injuries* ; Consensus ; Diagnosis, Differential ; Cone-Beam Computed Tomography ; Tooth Fractures/therapy*

Objective:To determine the incidence of acute focal bacterial nephritis (AFBN) in children with febrile urinary tract infections (UTI) and to identify associated risk factors.Methods:A retrospective cohort study included 181 children hospitalized with febrile UTI at Fujian Children′s Hospital from April 2021 to September 2023. Demographic data, clinical manifestations, and laboratory findings were collected. Patients were categorized into AFBN group and non-AFBN group based on AFBN diagnosis. The incidence of AFBN within this febrile UTI cohort was determined. The diagnostic value for pre-antibiotic blood white blood cell (WBC) count and C-reactive protein (CRP) level, along with post-treatment fever duration and pyuria duration for AFBN was evaluated using the area under curve (AUC) of the receiver operating characteristic (ROC).Results:The cohort comprised 181 children with febrile UTI (100 boys and 81 girls), age of 0.6 (0.3, 1.0) years. Eleven patients (6.1%) were diagnosed with AFBN. For predicting AFBN, the AUC was 0.71 (95% CI 0.55-0.85, P=0.026) for pre-antibiotic WBC count and 0.80 (95% CI 0.71-0.90, P=0.001) for pre-antibiotic CRP level, with optimal cutoff values of 16.0×10 9/L and 80.1 mg/L, respectively. For post-treatment parameters, the AUC was 0.79 (95% CI 0.69-0.92, P=0.001) for fever duration and 0.84 (95% CI 0.72-0.97, P<0.001) for pyuria duration, with optimal cutoff values of 1.9 d and 5.5 d, respectively. The combination of pre-antibiotic WBC count >16.0×10 9/L and CRP>80.1 mg/L yielded a sensitivity of 0.73 and a specificity of 0.86 for AFBN prediction. Similarly, the combination of post-treatment fever duration ≥2 d and pyuria duration >5 d demonstrated a sensitivity of 0.82 and specificity of 0.88. Conclusions:AFBN incidence was 6.1% in this cohort of children with febrile UTI. AFBN should be highly suspected in febrile UTI children presenting with either a pre-antibiotic WBC count >16.0×10 9/L and CRP >80.1 mg/L, or a post-treatment fever duration ≥2 d and pyuria duration >5 d.

Objective:To investigate the clinical characteristics of urea cycle disorder (UCD), the efficacy and safety of glyceryl phenylbutyrate (GPB) therapy in pediatric patients with UCD.Methods:This study was a retrospective, single-arm, multicenter clinical study. The clinical data of 20 pediatric patients with UCD who received GPB treatment at 9 hospitals nationwide between December 2021 and August 2024 were collected. The clinical manifestations, laboratory results, and molecular genetic characteristics were analyzed, ammonia levels and other laboratory results were evaluated pre-post GPB therapy by paired t-tests or Wilcoxon tests. Results:Among the 20 pediatric patients with UCD, there were 8 males and 12 females, and the onset age was 2.8 (1.4, 5.7) years. The ammonia levels were 174 (125, 342) μmol/L at first onset. The symptoms included vomiting in 6 cases, drowsiness in 5 cases, epilepsy in 5 cases, developmental delay in 5 cases, psychiatric and behavioral abnormalities in 3 cases, and lethargy in 1 case, and 18 cases exhibited abnormal liver function. Twenty cases included 6 UCD subtypes, with 11 cases being ornithine transcarbamylase deficiency. A total of 27 variants were identified, 11 (41%) of which were novel. The age of patients who began GPB therapy was 4.0 (1.5, 6.6) years. Ten cases stopped GPB after 4.2 (3.4, 5.3) months, with 4 patients undergoing liver transplantation and 6 discontinuing for financial reasons. The remaining ten patients continued GPB therapy for 11.6 (8.6, 14.0) months. The duration of GPB treatment was 6.0 (4.2, 12.3) months, at the final visit, the levels of ammonia, platelets and aspartate aminotransferase were lower compared to those of pre-treatment (all P<0.05). The serum albumin level was higher than that of pre-treatment ( P=0.016). Two patients suffered only one episode of acute hyperammonaemia, with ammonia levels of 232 and 141 μmol/L, respectively. Nine cases experienced adverse effects potentially related to GPB, decreased appetite in 6 cases, vomiting in 3 cases, abnormal skin oil odor in 2 cases, somnolence, fatigue and diarrhea each in 1 case, with symptoms improved within 6 (3, 10) days. Conclusions:UCD primarily manifests with neurological and gastrointestinal symptoms, and early diagnosis of UCD could be achieved through the analysis of ammonia. GPB may effectively reduce ammonia levels in UCD pediatric patients, with favorable safety and tolerability.

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

Objective To observe the clinical efficacy and safety of vericiguat tablets combined with sacubitril valsartan sodium(Sac/Val)tablets in the treatment of patients with heart failure with reduced ejection fraction(HFrEF).Methods The HFrEF patients were divided into control group and treatment group according to the cohort method.The control group was treated with Sac/Val tablets 200 mg per time,bid,orally.On the basis of control group,the treatment group was treated with vericiguat tablets 2.5 mg per time,qd,taken with meal.Two groups were treated for 3 months.The clinical efficacy,left ventricular ejection fraction(LVEF),left ventricular end-diastolic dimension(LVEDD)and end-systolic diameter(LVESD),levels of high sensitivity C-reactive protein(hs-CRP),interleukin-6(IL-6),nitric oxide(NO),N-terminal pro-brain natriuretic peptide(NT-proBNP),blood urea nitrogen(BUN)and serum creatinine(SCr),and safety were compared between the two groups.During follow-up,the heart failure rehospitalization rates and major adverse cardiovascular events were compared between the two groups.Results Treatment group was enrolled 53 patients,control group was enrolled 53 patients.After treatment,the total effective rates of treatment and control groups were 94.34％(50 cases/53 cases)and 81.13％(43 cases/53 cases)with statistical significant difference(P＜0.05).After treatment,the LVEF of treatment and control groups were(48.02±5.20)％and(43.02±4.33)％,the LVEDDs were(52.85±6.30)and(55.63±6.88)mm,the LVESDs were(41.64±6.40)and(44.22±5.85)mm,the levels of hs-CRP were(10.22±2.63)and(14.60±2.98)mg L-1,the levels of IL-6 were(14.48±2.40)and(17.36±2.52)pg·mL-1,the levels of NO were(102.60±20.16)and(92.16±16.33)μmol·L-1,the levels of NT-proBNP were(898.74±102.20)and(1315.60±182.64)ng·L-1,the levels of BUN were(12.02±2.28)and(13.45±2.33)mmol·L-1,the levels of SCr were(82.22±5.89)and(85.64±6.03)μmol·L-1,the heart failure rehospitalization rates were 5.66％and 13.21％,respectively;the differences were statistical significant between two groups(all P＜0.05).The adverse drug reactions of treatment group were hyperkalemia,hypotension,renal dysfunction,dizziness and headache,while those in control group were renal dysfunction,hyperkalemia,and hypotension.The major adverse cardiovascular events of treatment group were angina pectoris and acute myocardial infarction,while those in control group were angina pectoris,acute myocardial infarction and atrial fibrillation.The incidences of total adverse drug reactions in treatment and control groups were 13.21％and 7.55％,the incidences of major adverse cardiovascular events were 5.66％and 13.21％,respectively,without statistically significant differences(all P＞0.05).Conclusion Vericiguat tablets combined with Sac/Val tablets have a definitive clinical efficacy in the treatment of HFrEF patients,which can improve cardiac and endothelial function,reduce inflammatory response and readmission times,without increasing the incidences of adverse drug reactions.