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.

OBJECTIVES: To evaluate the impact of HBV infection on pre- and postpartum health-related quality of life (HRQoL) in pregnant women. METHODS: A prospective matched cohort consisting of 70 HBV-infected and 70 healthy pregnant women was recruited from the Fifth Affiliated Hospital of Guangzhou Medical University between April 17 and September 25, 2023. HRQoL of the participants was assessed at 16-24 weeks of gestation, between 32 weeks and delivery, and 5-13 weeks postpartum. Mixed linear models were used for evaluating temporal trends of HRQoL changes, and univariate ANOVA with multiple linear regression was used to identify the predictors of HRQoL. RESULTS: Compared with healthy pregnant women, HBV-infected pregnant women had consistently lower total HRQoL scores across all the 3 intervals, with the lowest scores observed between 32 weeks of gestation and delivery, during which these women had significantly reduced mental component scores (74.27±13.43 vs 80.21±12.9, P=0.009) and postpartum mental (76.52±16.19 vs 85.02±6.51, P<0.001) and physical component scale scores (77.17±14.71 vs 83.09±10.1, P=0.009). HBV infection was identified as an independent risk factor affecting HRQoL during late pregnancy and postpartum periods. Additional independent risk factors for postpartum HRQoL reduction included self-pay medical expenses, spouse's neutral attitude toward the current pregnancy, and preexisting comorbidities (all P<0.05). CONCLUSIONS HRQoL of pregnant women deteriorates progressively in late pregnancy, and HBV infection exacerbates reductions of physical function and role emotion in late pregnancy and after delivery, suggesting the importance of targeted interventions for financial burdens, partner support and comorbid conditions to improve HRQoL of pregnant women with HBV infection.
Humans ; Female ; Pregnancy ; Quality of Life ; Prospective Studies ; Postpartum Period ; Hepatitis B, Chronic/psychology* ; Adult ; Pregnancy Trimester, Third ; Pregnancy Trimester, Second ; Pregnancy Complications, Infectious

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 study the genetic polymorphism of red blood cell blood group among in Shenzhen Han, Indian and Xinjiang Uyghur populations, to provide scientific basis for the demand prediction and collection strategy of rare blood group, and to explore the genetic differences of blood group between Han and Caucasians. METHODS: The haplotypes of antigen coding genes of 10 target blood group systems from 87 Han Chinese and 50 Indian blood donors in Shenzhen, and 49 healthy Uyghur people in Xinjiang were obtained by three-generation sequencing technology, and the polymorphism and frequency characteristics were analyzed. RESULTS: Only a single genotype was detected the Langereis and Vel blood group systems in samples from three different populations. Only one genotype of Dombrock blood group was detected in Shenzhen Han, and Junior blood group in Xinjiang Uygur populations. In the MNS, Duffy, Kidd, Dombrock and Junior blood group systems, the haplotype frequency of Indian and Uyghur people was significantly different from that of Han people. Compared with the Han ethnic group, the rare blood group s-, Fy(a-), Jk(a-b-), and Do(a+b-) have a higher frequency among the Uyghur and Indian populations. CONCLUSION Haplotype frequencies of antigen genes for MNS, Duffy, Kidd, Dombrock and Junior blood group system in Shenzhen Han, Indian and Uyghur populations displayed a polymorphic difference with unique distribution characteristics different from the ethnic groups in other regions.
Humans ; Blood Group Antigens/genetics* ; China/ethnology* ; Erythrocytes ; Ethnicity/genetics* ; Gene Frequency ; Genotype ; Haplotypes ; India/ethnology* ; Polymorphism, Genetic ; White People/genetics* ; Central Asian People/genetics* ; East Asian People/genetics*

OBJECTIVE: Emerging evidence suggests that exposure to ultrafine particulate matter (UPM, aerodynamic diameter < 0.1 µm) is associated with adverse cardiovascular events. Previous studies have found that Shenlian (SL) extract possesses anti-inflammatory and antiapoptotic properties and has a promising protective effect at all stages of the atherosclerotic disease process. In this study, we aimed to investigated whether SL improves UPM-aggravated myocardial ischemic injury by inhibiting inflammation and cell apoptosis. METHODS: We established a mouse model of MI+UPM. Echocardiographic measurement, measurement of myocardialinfarct size, biochemical analysis, enzyme-linked immunosorbent assay (ELISA), histopathological analysis, Transferase dUTP Nick End Labeling (TUNEL), Western blotting (WB), Polymerase Chain Reaction (PCR) and so on were used to explore the anti-inflammatory and anti-apoptotic effects of SL in vivo and in vitro. RESULTS: SL treatment can attenuate UPM-induced cardiac dysfunction by improving left ventricular ejection fraction, fractional shortening, and decreasing cardiac infarction area. SL significantly reduced the levels of myocardial enzymes and attenuated UPM-induced morphological alterations. Moreover, SL significantly reduced expression levels of the inflammatory cytokines IL-6, TNF-α, and MCP-1. UPM further increased the infiltration of macrophages in myocardial tissue, whereas SL intervention reversed this phenomenon. UPM also triggered myocardial apoptosis, which was markedly attenuated by SL treatment. The results of in vitro experiments revealed that SL prevented cell damage caused by exposure to UPM combined with hypoxia by reducing the expression of the inflammatory factor NF-κB and inhibiting apoptosis in H9c2 cells. CONCLUSION Overall, both in vivo and in vitro experiments demonstrated that SL attenuated UPM-aggravated myocardial ischemic injury by inhibiting inflammation and cell apoptosis. The mechanisms were related to the downregulation of macrophages infiltrating heart tissues.
Animals ; Apoptosis/drug effects* ; Particulate Matter/adverse effects* ; Mice ; Male ; Inflammation/drug therapy* ; Drugs, Chinese Herbal/therapeutic use* ; Mice, Inbred C57BL ; Myocardial Ischemia/drug therapy* ; Cell Line

Objective:To establish a liquid chromatography tandem mass spectrometry (LC-MS/MS) method for accurate determination of plasma Lyso-GL-3 concentration.Method:Solid phase extraction technology was used to process plasma samples, and under positive ion mode and multiple reaction monitoring (MRM) conditions, LC-MS/MS was used to determine the concentration of Lyso-GL-3. The linear range, detection and quantification limits, accuracy, precision, matrix effect, carrier effect of the method, and plasma sample stability were validated. And the accuracy of Lyso-GL-3 positive patients was compared by combining enzymatic and genetic testing results.Result:Lyso-GL-3 had good linearity in the range of 1.25-400 nmol/L. The detection limit and quantification limit were 0.15 nmol/L and 0.50 nmol/L, respectively. The spiked recovery rate was 88.78%-108.96%. The coefficient of variation ( CV) for intra batch precision, inter batch precision, and matrix effect were all less than 15%, the result of carrier effect was 0.55%. Plasma samples could be stably stored for 30 days under refrigeration conditions. The clinical conformity of the patient was 100%. Conclusion:The established LC-MS/MS detection method for plasma Lyso-GL-3 concentration takes 2.5 minutes, which is simple, fast, accurate, and reliable.

BACKGROUND: While emotional distress, encompassing anxiety and depression, has been associated with negative clinical outcomes, its impact across various clinical departments and general hospitals has been less explored. Previous studies with limited sample sizes have examined the effectiveness of specific treatments (e.g., antidepressants) rather than a systemic management strategy for outcome improvement in non-psychiatric inpatients. To enhance the understanding of the importance of addressing mental health care needs among non-psychiatric patients in general hospitals, this study retrospectively investigated the impacts of emotional distress and the effects of early detection and management of depression and anxiety on hospital length of stay (LOS) and rate of long LOS (LLOS, i.e., LOS >30 days) in a large sample of non-psychiatric inpatients. METHODS: This retrospective cohort study included 487,871 inpatients from 20 non-psychiatric departments of a general hospital. They were divided, according to whether they underwent a novel strategy to manage emotional distress which deployed the Huaxi Emotional Distress Index (HEI) for brief screening with grading psychological services (BS-GPS), into BS-GPS ( n = 178,883) and non-BS-GPS ( n = 308,988) cohorts. The LOS and rate of LLOS between the BS-GPS and non-BS-GPS cohorts and between subcohorts with and without clinically significant anxiety and/or depression (CSAD, i.e., HEI score ≥11 on admission to the hospital) in the BS-GPS cohort were compared using univariable analyses, multilevel analyses, and/or propensity score-matched analyses, respectively. RESULTS: The detection rate of CSAD in the BS-GPS cohort varied from 2.64% (95% confidence interval [CI]: 2.49%-2.81%) to 20.50% (95% CI: 19.43%-21.62%) across the 20 departments, with a average rate of 5.36%. Significant differences were observed in both the LOS and LLOS rates between the subcohorts with CSAD (12.7 days, 535/9590) and without CSAD (9.5 days, 3800/169,293) and between the BS-GPS (9.6 days, 4335/178,883) and non-BS-GPS (10.8 days, 11,483/308,988) cohorts. These differences remained significant after controlling for confounders using propensity score-matched comparisons. A multilevel analysis indicated that BS-GPS was negatively associated with both LOS and LLOS after controlling for sociodemographics and the departments of patient discharge and remained negatively associated with LLOS after controlling additionally for the year of patient discharge. CONCLUSION Emotional distress significantly prolonged the LOS and increased the LLOS of non-psychiatric inpatients across most departments and general hospitals. These impacts were moderated by the implementation of BS-GPS. Thus, BS-GPS has the potential as an effective, resource-saving strategy for enhancing mental health care and optimizing medical resources in general hospitals.
Humans ; Retrospective Studies ; Male ; Length of Stay/statistics & numerical data* ; Female ; Middle Aged ; Adult ; Psychological Distress ; Inpatients/psychology* ; Aged ; Anxiety/diagnosis* ; Depression/diagnosis*

Objective To assess the predictive value of proprotein convertase subtilisin/kexin type-9(PCSK9)combined with lactic acid(Lac)and Sequential Organ Failure Assessment(SOFA)score in determining the 28-day mortality risk of patients with sepsis.Methods A total of 203 patients with sepsis were followed up for 28 days.Patients were divided into the death group(n=56)and the survival group(n=147)according to the clinical outcome.The general data and clinical indicators were compared between the two groups.The prediction model of 28 day mortality risk of sepsis patients was established by multivariate Logistic regression analysis,and the nomogram of the prediction model visualization was drawn.Results Alanine aminotransferase,serum creatinine,blood urea nitrogen,Lac,PCSK9 and SOFA score were higher in the death group than those in the survival group(P＜0.05),while the hemoglobin level was lower than that in the survival group(P＜0.05).The multivariable Logistic regression analysis identified that elevated levels of Lac(OR=1.197,95％CI:1.019-1.435),PCSK9(OR=1.002,95％CI:1.001-1.003)and SOFA score(OR=1.858,95％CI:1.528-2.340)were independent risk factors for 28-day mortality in patients with sepsis(P＜0.05).Nomogram was developed using these three indicators,and the linear predictor cutoff value was-1.06.Patients were divided into the low-risk group(n=126)and the high-risk group(n=77).The 28-day mortality rates were 4.0％for the low-risk group and 66.2％for the high-risk group.Internal validation showed that the model with these three indicators had good discrimination(C-index=0.924,95％CI:0.881～0.960,P＜0.05),calibration(x2=11.543,P＞0.05)and clinical utility.Conclusion The combination of serum PCSK9,Lac and SOFA scores at admission effectively predicts 28-day mortality risk in sepsis patients.

Objective To assess the predictive value of proprotein convertase subtilisin/kexin type-9(PCSK9)combined with lactic acid(Lac)and Sequential Organ Failure Assessment(SOFA)score in determining the 28-day mortality risk of patients with sepsis.Methods A total of 203 patients with sepsis were followed up for 28 days.Patients were divided into the death group(n=56)and the survival group(n=147)according to the clinical outcome.The general data and clinical indicators were compared between the two groups.The prediction model of 28 day mortality risk of sepsis patients was established by multivariate Logistic regression analysis,and the nomogram of the prediction model visualization was drawn.Results Alanine aminotransferase,serum creatinine,blood urea nitrogen,Lac,PCSK9 and SOFA score were higher in the death group than those in the survival group(P＜0.05),while the hemoglobin level was lower than that in the survival group(P＜0.05).The multivariable Logistic regression analysis identified that elevated levels of Lac(OR=1.197,95％CI:1.019-1.435),PCSK9(OR=1.002,95％CI:1.001-1.003)and SOFA score(OR=1.858,95％CI:1.528-2.340)were independent risk factors for 28-day mortality in patients with sepsis(P＜0.05).Nomogram was developed using these three indicators,and the linear predictor cutoff value was-1.06.Patients were divided into the low-risk group(n=126)and the high-risk group(n=77).The 28-day mortality rates were 4.0％for the low-risk group and 66.2％for the high-risk group.Internal validation showed that the model with these three indicators had good discrimination(C-index=0.924,95％CI:0.881～0.960,P＜0.05),calibration(x2=11.543,P＞0.05)and clinical utility.Conclusion The combination of serum PCSK9,Lac and SOFA scores at admission effectively predicts 28-day mortality risk in sepsis patients.

Objective:To establish a liquid chromatography tandem mass spectrometry (LC-MS/MS) method for accurate determination of plasma Lyso-GL-3 concentration.Method:Solid phase extraction technology was used to process plasma samples, and under positive ion mode and multiple reaction monitoring (MRM) conditions, LC-MS/MS was used to determine the concentration of Lyso-GL-3. The linear range, detection and quantification limits, accuracy, precision, matrix effect, carrier effect of the method, and plasma sample stability were validated. And the accuracy of Lyso-GL-3 positive patients was compared by combining enzymatic and genetic testing results.Result:Lyso-GL-3 had good linearity in the range of 1.25-400 nmol/L. The detection limit and quantification limit were 0.15 nmol/L and 0.50 nmol/L, respectively. The spiked recovery rate was 88.78%-108.96%. The coefficient of variation ( CV) for intra batch precision, inter batch precision, and matrix effect were all less than 15%, the result of carrier effect was 0.55%. Plasma samples could be stably stored for 30 days under refrigeration conditions. The clinical conformity of the patient was 100%. Conclusion:The established LC-MS/MS detection method for plasma Lyso-GL-3 concentration takes 2.5 minutes, which is simple, fast, accurate, and reliable.