Objective: To develop a convenient, direct, and highly sensitive method for screening trace chemical additives in complex Chinese patent medicines, thereby addressing core technological bottlenecks in pharmaceutical analysis and quality control. Methods: A brush ionization probe device was independently designed and constructed, and an efficient detection method was established through systematic optimization of key parameters. Twenty-three Chinese patent medicine samples, representing 6 dosage forms (capsules, tablets, pills, granules, powders, and liquid preparations), were analyzed using 10 common chemical additives as target analytes. Results: All samples were successfully analyzed without complex pretreatment, and 5 chemical additives were detected in 7 Chinese patent medicines. The brush ionization probe device exhibited cost-effectiveness (~0.2 USD per probe), operational simplicity, rapid analysis (~10s per sample), high efficiency, and minimal reagent consumption (~10 μL per sample). Conclusion: This advancement is expected to provide an innovative scientific tool for improving the generality and convenience of on-site quality control, while promoting technological progress in disciplines such as pharmacology and traditional Chinese medicine.

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 establish a mouse model of liver cancer resistant to PD-1 monoclonal antibody and analyze the changes in its metabolomics to explore the potential mechanism of drug resistance.Methods:BALB/c mice were randomly divided into control and treatment groups after being loaded with tumor,and a normal group was additionally set up.The normal and control groups were injected with saline,and the treatment group was injected with PD-1 monoclonal antibody,after which the mice in the treatment group were screened for drug resistant and response groups.Observed the drug-resistant situation,body mass,tumor growth and survival rate of mice in each group,calculate the spleen index.The pathological features of tumor tissues were observed by HE staining method.Serum metabolites were detected by non-targeted metabolomics.Finally,a bivariate Pearson correlation analysis was conducted between the differential serum metabolites and tumor size.Results:The tumor-bearing mouse model with PD-1 monoclonal antibody resistance was successfully established,and the drug resistance rate of the mice was 50％.Compared with the normal and response groups,mice in the resistant group showed an increase in body weight,a significant increase in tumor volume,a decrease in survival rate,and a significant increase in splenic index.There was less lymphocyte infiltration in the tumor tissue.Metabolomics analysis showed that the serum levels of glutamic acid and aspartic acid increased and malic acid decreased in the resistant mice compared with the response group,and these changes were closely related to the arginine biosynthesis pathway.Conclusions:The tumor-bearing mouse model with PD-1 monoclonal antibody resistance was successfully established.The changes in its peripheral serum metabolomics mainly involve arginine metabolism and the related changes of aspartate,malate and glutamate.

Objective:To investigate the value of 0.55 T MRI scanner using deep-learning (DL) reconstruction in evaluating pulmonary tumors.Methods:The study was a cross-sectional study. Sixty-one patients with pulmonary tumors on CT images were prospectively collected from May to September 2024 in Peking University First Hospital, including 37 males and 24 females, and aged 46?89 (68±9) years old. All patients underwent lung scan on a 0.55 T MRI, using diffusion weighted imaging(DWI) sequence with b-values of 0 and 800 s/mm 2. According to whether DL reconstruction was used and the number of acquisitions, they were divided into DWI-DL 5∶30 group (DL, number of averages=10, acquisition time=5 min 30 s),DWI-DL 3∶22 group (DL, number of averages=5, acquisition time=3 min 22 s), and DWI-C group (GRAPPA, number of averages=10, acquisition time=5 min 30 s). The obtained images were evaluated subjectively (Likert score) and objectively [signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR)]. Meanwhile the apparent diffusion coefficient (ADC) value of the tumors was measured. Friedman nonparametric test was used for comparison among the three groups and Bonferroni method was used for pairwise comparison. Results:The subjective scores, SNR, and CNR were significantly different among DWI-DL 5∶30 group, DWI-DL 3∶22 group, and DWI-C group( χ 2=9.69,87.56,88.62, P=0.008,<0.001,<0.001). Bonferroni method results showed that the subjective scores, SNR, and CNR of DWI-DL 5∶30 group were higher than those of DWI-DL 3∶22 group and DWI-C group ( P<0.05); However, the subjective scores, SNR, and CNR did not significantly differ between DWI-DL 3∶22 group and DWI-C group ( P>0.05). The ADC values of the tumors were not significantly different among DWI-DL 5∶30 group, DWI-DL 3∶22 group, and DWI-C group (χ 2=5.95, P=0.510). Conclusion:The DWI reconstructed using DL has better or similar image quality to conventional DWI in evaluating pulmonary tumors and significantly reduces scanning time, which has certain clinical application value.

To construct a recombinant fowl adenovirus 4(FAdV-4)expressing the Cap protein of goose astrovirus genotype 2(GoAstV-2),the expression cassette of Cap gene was inserted into the natural 1 966 bp deletion region of the FAdV-4 genome in the infectious clone p15A-cm-FAdV4-HNJZ.The resulted recombinant plasmid p15A-cm-FAdV4-HNJZ-Cap/GoAstV-2 was linearized with restriction enzyme and transfected into chicken hepatoma cell line(LMH)to rescue the recombinant FAdV-4 expressing the Cap protein of GoAstV-2,rF Ad V4-Cap/GoAstV-2.After 15 passages in LMH cells,the recombinant rFAdV4-Cap/GoAstV-2 was identified by PCR using primers flanking the insertion site of the Cap gene expression cassette and using viral genome DNA extracted from rFAdV4-Cap/GoAstV-2 infected LMH cells as template.LMH cells were in-fected with 15th passage rFAdV4-Cap/GoAstV-2 and indirect immunofluorescence was performed with a polyclonal antibody against Cap protein as the primary antibody.Western blot was carried out with lysates of rFAdV4-Cap/GoAstV-2 infected LMH cells.The in vitro replication dynamic of the 15th passage of the rFAdV4-Cap/GoAstV-2 was also investigated in LMH cells.The results demonstrated that the Cap gene of GoAstV-2 was presented in the genome of the recombinant vi-rus rF AdV4-Cap/Go Ast V-2,and could be expressed stably.The prepared recombinant virus in this study will lay a foundation for developing inactivated bivalent vaccine candidate against co-in-fection of FAdV-4 and GoAstV-2 in goose.

There is significant inter-individual variation of pharmacokinetics and pharmacody-namics in patients receiving tacrolimus(TAC)for an-ti-rejection therapy,which cause the rejection or toxic action.Based on results of therapeutic drug monitoring and pathophysiological index of trans-plant patients,the individualized dosing regimen can be designed and adjusted by using model in-formed precision dosing(MIPD).The patients'clini-cal outcome can be improved.In the consensus,the different methods of MIPD used for patients re-ceived TAC for anti-rejection therapy were intro-duced,which can be used for the designing and ad-justing doing regimen,predicting adverse drug reac-tion,improving medication adherence and econom-ics during therapy.

Objective:To establish a mouse model of liver cancer resistant to PD-1 monoclonal antibody and analyze the changes in its metabolomics to explore the potential mechanism of drug resistance.Methods:BALB/c mice were randomly divided into control and treatment groups after being loaded with tumor,and a normal group was additionally set up.The normal and control groups were injected with saline,and the treatment group was injected with PD-1 monoclonal antibody,after which the mice in the treatment group were screened for drug resistant and response groups.Observed the drug-resistant situation,body mass,tumor growth and survival rate of mice in each group,calculate the spleen index.The pathological features of tumor tissues were observed by HE staining method.Serum metabolites were detected by non-targeted metabolomics.Finally,a bivariate Pearson correlation analysis was conducted between the differential serum metabolites and tumor size.Results:The tumor-bearing mouse model with PD-1 monoclonal antibody resistance was successfully established,and the drug resistance rate of the mice was 50％.Compared with the normal and response groups,mice in the resistant group showed an increase in body weight,a significant increase in tumor volume,a decrease in survival rate,and a significant increase in splenic index.There was less lymphocyte infiltration in the tumor tissue.Metabolomics analysis showed that the serum levels of glutamic acid and aspartic acid increased and malic acid decreased in the resistant mice compared with the response group,and these changes were closely related to the arginine biosynthesis pathway.Conclusions:The tumor-bearing mouse model with PD-1 monoclonal antibody resistance was successfully established.The changes in its peripheral serum metabolomics mainly involve arginine metabolism and the related changes of aspartate,malate and glutamate.

There is significant inter-individual variation of pharmacokinetics and pharmacody-namics in patients receiving tacrolimus(TAC)for an-ti-rejection therapy,which cause the rejection or toxic action.Based on results of therapeutic drug monitoring and pathophysiological index of trans-plant patients,the individualized dosing regimen can be designed and adjusted by using model in-formed precision dosing(MIPD).The patients'clini-cal outcome can be improved.In the consensus,the different methods of MIPD used for patients re-ceived TAC for anti-rejection therapy were intro-duced,which can be used for the designing and ad-justing doing regimen,predicting adverse drug reac-tion,improving medication adherence and econom-ics during therapy.

This research aimed to comprehensively understand the prevalence of mutation in drug-resistant molecular markers of imported Plasmodium vivax in Chongqing,the Pvmdr1,Pvdhps,Pvdhfr,Pvcrt-o and Pvk12 genes of Plasmodium vivax were systematically analyzed.Blood samples were collected from imported Plasmodium vivax-infected patients in Chongqing between 2011 and 2022.The Pvmdr1,Pvdhps,Pvdhfr,Pvcrt-o,and Pvk12 genes were amplified and then sequenced to precisely evaluate gene mutations.Bioinformatics methods were employed to conduct in depth analysis of the mutation prevalence.Regarding the Pvdhfr gene,mutations at codons 50,57,58,61,99,117,and 199 were detected in 2.9%,23.5%,76.4%,23.53%,2.9%,82.3%,and 5.88%of the samples,respectively.The double-mutant haplotype S58R/S117N was the most prevalent,accounting for 50%,followed by the quadruple-mutant haplotype F57L/S58R/T61M/S117T,which accounted for 11.76%.Among the four types of tandem-repeat variations of Pvdhfr,the wild-type was the most common,and the insertion type was a novel discovery in this study.For the Pvdhps gene,the prevalence among mutation genotypes was relatively low.The single-mutant genotype was dominant,constituting 27.03%.The prevalence of Pvmdr1 mutations at codons 958 and 1076 was 100%and 89.19%,respectively.Among the 37 successfully sequenced samples,K10 insertion was detected in only 8 cases(22.22%).Notably,no non-synonymous mutations of Pvk12 were identified in this study.The cases in this study were imported from various countries of origin.Novel tandem-repeat variation tyres of Pvdhfr and new mutation sites of Pvdhps were identifide,thus enriching the mutation information of imported Plasmodium vivax resistance molecular markers in China.

Parathyromegaly refers to chronic enlargement of the parathyroid glands caused by multiple etiological factors. Pathological conditions, such as hyperparathyroidism, parathyroid hyperfunction, parathyroid adenoma, parathyroid cysts, and parathyroid carcinoma may all lead to parathyromegaly. Notably, calcium intake insufficiency and/or vitamin D insufficiency (CVI), which is the predominant etiology of parathyromegaly, now has been recognized as a global public health challenge. Chronic CVI induces negative calcium balance and relative low serum calcium level, stimulating compensatory parathyroid hyperplasia and enlargement. This progression triggers parathyroid hyperfunction and secondary hyperparathyroidism, resulting in bone mass loss, height reduction, kyphosis, osteoporosis, pathological fractures, metastatic vascular calcification and systemic abnormal calcium migration and calcinosis (such as urolithiasis). During the early stages of parathyromegaly, the condition remains preventable and treatable; However, delayed intervention may lead to irreversible tertiary hyperparathyroidism. CVI-associated parathyromegaly exhibits high prevalence and heterogeneous clinical manifestations, representing a critically underrecognized clinical entity. This article will systematically discuss the etiology, pathological characteristics, clinical consequences, and prevention and control strategies for CVI-related parathyromegaly.