Immobilized enzyme-based enzyme electrode biosensors, characterized by high sensitivity and efficiency, strong specificity, and compact size, demonstrate broad application prospects in life science research, disease diagnosis and monitoring, etc. Immobilization of enzyme is a critical step in determining the performance (stability, sensitivity, and reproducibility) of the biosensors. Random immobilization (physical adsorption, covalent cross-linking, etc.) can easily bring about problems, such as decreased enzyme activity and relatively unstable immobilization. Whereas, directional immobilization utilizing amino acid residue mutation, affinity peptide fusion, or nucleotide-specific binding to restrict the orientation of the enzymes provides new possibilities to solve the problems caused by random immobilization. In this paper, the principles, advantages and disadvantages and the application progress of enzyme electrode biosensors of different directional immobilization strategies for enzyme molecular sensing elements by specific amino acids (lysine, histidine, cysteine, unnatural amino acid) with functional groups introduced based on site-specific mutation, affinity peptides (gold binding peptides, carbon binding peptides, carbohydrate binding domains) fused through genetic engineering, and specific binding between nucleotides and target enzymes (proteins) were reviewed, and the application fields, advantages and limitations of various immobilized enzyme interface characterization techniques were discussed, hoping to provide theoretical and technical guidance for the creation of high-performance enzyme sensing elements and the manufacture of enzyme electrode sensors.

T7 RNA polymerase (T7 RNAP) is one of the simplest known RNA polymerases. Its unique structural features make it a critical model for studying the mechanisms of RNA synthesis. This review systematically examines the static crystal structure of T7 RNAP, beginning with an in-depth examination of its characteristic “thumb”, “palm”, and “finger” domains, which form the classic “right-hand-like” architecture. By detailing these structural elements, this review establishes a foundation for understanding the overall organization of T7 RNAP. This review systematically maps the functional roles of secondary structural elements and their subdomains in transcriptional catalysis, progressively elucidating the fundamental relationships between structure and function. Further, the intrinsic flexibility of T7 RNAP and its applications in research are also discussed. Additionally, the review presents the structural diagrams of the enzyme at different stages of the transcription process, and through these diagrams, it provides a detailed description of the complete transcription process of T7 RNAP. By integrating structural dynamics and kinetics analyses, the review constructs a comprehensive framework that bridges static structure to dynamic processes. Despite its advantages, T7 RNAP has a notable limitation: it generates double-stranded RNA (dsRNA) as a byproduct. The presence of dsRNA not only compromises the purity of mRNA products but also elicits nonspecific immune responses, which pose significant challenges for biotechnological and therapeutic applications. The review provides a detailed exploration of the mechanisms underlying dsRNA formation during T7 RNAP catalysis, reviews current strategies to mitigate this issue, and highlights recent progress in the field. A key focus is the semi-rational design of T7 RNAP mutants engineered to minimize dsRNA generation and enhance catalytic performance. Beyond its role in transcription, T7 RNAP exhibits rapid development and extensive application in fields, including gene editing, biosensing, and mRNA vaccines. This review systematically examines the structure-function relationships of T7 RNAP, elucidates the mechanisms of dsRNA formation, and discusses engineering strategies to optimize its performance. It further explores the engineering optimization and functional expansion of T7 RNAP. Furthermore, this review also addresses the pressing issues that currently need resolution, discusses the major challenges in the practical application of T7 RNAP, and provides an outlook on potential future research directions. In summary, this review provides a comprehensive analysis of T7 RNAP, ranging from its structural architecture to cutting-edge applications. We systematically examine: (1) the characteristic right-hand domains (thumb, palm, fingers) that define its minimalistic structure; (2) the structure-function relationships underlying transcriptional catalysis; and (3) the dynamic transitions during the complete transcription cycle. While highlighting T7 RNAP’s versatility in gene editing, biosensing, and mRNA vaccine production, we critically address its major limitation—dsRNA byproduct formation—and evaluate engineering solutions including semi-rationally designed mutants. By synthesizing current knowledge and identifying key challenges, this work aims to provide novel insights for the development and application of T7 RNAP and to foster further thought and progress in related fields.

The efficacy of Xiangmei Pills on rats with ulcerative colitis(UC) was investigated by characterizing the spectrum of the active chemical components of Xiangmei Pills. Rapid identification and classification of the main chemical components were performed,and the therapeutic effects of Xiangmei Pills on the proteins and intestinal flora of UC rats were analyzed to explore the mechanism of its action in treating UC. Fifty SD rats were acclimatized to feeding for 3 d and randomly divided into blank group, model group,mesalazine group(0. 4 g·kg~(-1)), low-dose group of Xiangmei Pills(1. 89 g·kg~(-1)), and high-dose group of Xiangmei Pills(5. 67 g·kg~(-1)), with 10 rats in each group. 5% dextrose sodium sulfate(DSS) was given by gavage to induce the male SD rat model with UC,and the corresponding medicinal solution was given by gavage after 10 days, respectively. The therapeutic effect of Xiangmei Pills on rats with UC was evaluated according to body mass, disease activity index(DAI), and hematoxylin-eosin(HE) staining, and the histopathological changes in the colon were observed. Ultra-high performance liquid chromatography-quadrupole/electrostatic field orbitrap high-resolution mass spectrometry(UHPLC-Q-Orbitrap HRMS) technique was used to rapidly and accurately identify the main chemical constituents of Xiangmei Pills. Immunohistochemistry was used to detect the expression of aryl hydrocarbon receptor(AhR),interferon-γ(IFN-γ), mucin-2(MUC-2), and cytochrome P450 1A1(CYP1A1) in colon tissue. Interleukin-22(IL-22) expression in colon tissue was detected by immunofluorescence. The 16S r DNA high-throughput sequencing technique was used to study the modulatory effects of Xiangmei Pills on the intestinal flora structure of rats with UC. Pharmacodynamic results showed that compared with that of the blank group, the colon tissue of the model group was congested, and ulcers were visible in the mucosa; compared with that in the model group, the histopathology of the colon of the rats with UC in the groups of Xiangmei Pills were improved, with scattered ulcers and reduced inflammatory cell infiltration. Chemical analysis showed that a total of 45 components were identified by mass spectrometry information, including 15 phenolic acids, 8 coumarins, 15 organic acids, 3 amino acids, 2 flavonoids, and 2 other components. Compared with those in the blank group, the levels of Ah R, CYP1A1, MUC-2, and IL-22 proteins in the colon tissue of rats in the model group were significantly decreased, and the level of IFN-γ protein was significantly increased; the intestinal flora of rats in the model group was disorganized, with a decrease in the abundance of the flora; the relative abundance of Bacteroidetes,unclassified genera of Ascomycetes, Prevotella of the Prevotella family, and Prevotella decreased significantly, and that of Firmicutes decreased, but the difference was not statistically significant. The relative abundance of Bacteroidetes, Bifidobacterium, and Lactobacillus increased significantly. Compared with those of the model group, the levels of Ah R, CYP1A1, MUC-2, and IL-22proteins in the colonic tissue of the groups of Xiangmei Pills were significantly higher, and the levels of IFN-γ proteins were significantly lower. The recovery of the intestinal flora was accelerated, and the diversity of the intestinal flora was significantly increased. The relative abundance of Bacteroidetes was significantly increased, and that of unclassified genera of Ascomycetes,Lactobacillus, Prevotella of the Prevotella family, and Prevotella was significantly increased. The relative abundance of Bacteroidetes and Bifidobacterium was significantly decreased. This study demonstrated that Xiangmei Pills can effectively treat UC, mainly through the phenolic acid and organic acid components to stimulate the intestinal barrier, regulate protein expression and the relative abundance and diversity of intestinal flora, and play a role in the treatment of UC.
Animals ; Colitis, Ulcerative/metabolism* ; Drugs, Chinese Herbal/chemistry* ; Rats, Sprague-Dawley ; Male ; Rats ; Gastrointestinal Microbiome/genetics* ; Chromatography, High Pressure Liquid ; Humans ; Mass Spectrometry ; RNA, Ribosomal, 16S/genetics* ; Bacteria/drug effects*

This study aims to explore the scientific connotation of sinking Rehmanniae Radix has the best quality and compare the quality between floating and sinking fresh Rehmanniae Radix samples. Ultra-performance liquid chromatography tandem quadrupole electrostatic field Orbitrap high-resolution mass spectrometry(UHPLC-Q-Orbitrap HRMS) was employed to detect the chemical components in floating and sinking fresh Rehmanniae Radix samples. The fingerprint of fresh Rehmanniae Radix was established by high performance liquid chromatography(HPLC), and four index components were determined simultaneously. The cluster analysis, principal component analysis(PCA), and orthogonal partial least squares-discriminant analysis(OPLS-DA) were conducted to compare the quality of floating and sinking fresh Rehmanniae Radix samples. An evaporative light-scattering detector was used to compare the content of five sugars. The extract yield and drying rate were determined, and the quality connotation of sinking Rehmanniae Radix has the best quality was explained by multiple indicators. A total of 41 components were preliminarily identified from fresh Rehmanniae Radix by UHPLC-Q-Orbitrap HRMS, including 7 iridoid glycosides, 9 phenylethanol glycosides, 6 amino acids, 4 sugars, 3 phenolic acids, 5 nucleosides, 3 organic acids, 1 ionone, 1 furan, 1 coumarin, and 1 phenylpropanoid. The results showed that the main chemical components were consistent between floating and sinking fresh Rehmanniae Radix. Nine common peaks were identified in the fingerprints of 15 batches of floating and sinking fresh Rehmanniae Radix samples, and the similarity of fingerprints was greater than 0.9. The cluster analysis, PCA, and OPLS-DA classified floating and sinking fresh Rehmanniae Radix sasmples into two categories, indicating differences in the quality between them. The total content of catalpol, rehmannioside D, ajugol, and verbascoside in sinking fresh Rehmanniae Radix samples was higher than that in floating samples of the same batch and specification, and the main differential component was catalpol. The total content of fructose, glucose, sucrose, raffinose, and stachyose in sinking fresh Rehmanniae Radix samples was higher than that in floating samples of the same batch and specification, and the main differential component was stachyose. The extract yield and drying rate of the sinking samples were higher than those of floating samples. This study preliminarily showed that floating and sinking fresh Rehmanniae Radix samples had the same components but great differences in the content of medicinal substance basis. The total content of four glycosides and five sugars, extract yield, and drying rate of sinking fresh Rehmanniae Radix samples is higher than that of floating samples of the same batch and specification. These findings, to a certain extent, explains the scientificity of sinking Rehmanniae Radix has the best quality recorded in ancient books and provide a reference for the quality control and clinical application of fresh Rehmanniae Radix.
Chromatography, High Pressure Liquid/methods* ; Drugs, Chinese Herbal/chemistry* ; Rehmannia/chemistry* ; Chemometrics ; Mass Spectrometry/methods* ; Quality Control ; Principal Component Analysis ; Plant Extracts

Diabetic foot (DF) is one of the most serious chronic complications of diabetes. The incidence rate among global diabetes patients is as high as 15% to 25%, and about 50% of patients will develop contralateral foot ulcers within 5 years after the first unilateral ulcer. As a non-invasive prevention and control solution, the application progress of functional insoles is mainly reflected in the following aspects:(1) Material innovation. The application of new composite materials and smart materials has significantly enhanced the pressure reduction effect and comfort. (2) Structural optimization. The development of multi-layer design and local pressure reduction structure has achieved more precise pressure distribution regulation. (3) Manufacturing process. 3D printing and parametric design have enabled the personalized customization of functional insoles. (4) Intelligent monitoring. It integrates functions such as pressure sensing and temperature monitoring, achieving real-time monitoring and early warning of foot conditions. Clinical research has confirmed that personalized functional insoles could reduce the incidence of foot ulcers and shorten the healing time of ulcers. At present, the research hotspots mainly focus on the development of smart materials, the construction of multi-functional integration and remote monitoring systems. However, in-depth research is still needed in the aspects of biomechanical mechanisms, standardized evaluation systems and long-term efficacy assessment. The development of future functional insoles should focus on the coordinated advancement of "personalization-intelligence-standardization", with the aim of providing more effective solutions for the prevention and treatment of DF.
Humans ; Diabetic Foot/therapy* ; Foot Orthoses

OBJECTIVES: To determine the pharmacological impact of hesperidin, the main component of Citri Reticulatae Pericarpium, on depressive behavior and elucidate the mechanism by which hesperidin treats depression, focusing on the gut-brain axis. METHODS: Fifty-four Sprague Dawley male rats were randomly allocated to 6 groups using a random number table, including control, model, hesperidin, probiotics, fluoxetine, and Citri Reticulatae Pericarpium groups. Except for the control group, rats in the remaining 5 groups were challenged with chronic unpredictable mild stress (CUMS) for 21 days and housed in single cages. The sucrose preference test (SPT), immobility time in the forced swim test (FST), and number in the open field test (OFT) were performed to measure the behavioral changes in the rats. Enzyme-linked immunosorbent assay was used to determine the levels of 5-hydroxytryptamine (5-HT) and brain-derived neurotrophic factor (BDNF) in brain tissue, and the histopathology was performed to evaluate the changes of colon tissue, together with sequencing of the V3-V4 regions of 16S rRNA gene on feces to explore the changes of intestinal flora in the rats. RESULTS: Compared to the control group, the rats in the model group showed notable reductions in body weight, SPF, and number in OFT (P<0.01). Hesperidin was found to ameliorate depression induced by CUMS, as seen by improvements in body weight, SPT, immobility time in FST, and number in OFT (P<0.05 or P<0.01). Regarding neurotransmitters, it was found that at a dose of 50 mg/kg hesperidin treatment upregulated the levels of 5-HT and BDNF in depressed rats (P<0.05). Compared to the control group, the colon tissue of the model group exhibited greater inflammatory cell infiltration, with markedly reduced numbers of goblet cells and crypts and were significantly improved following treatment with hesperidin. Simultaneously, the administration of hesperidin demonstrated a positive impact on the gut microbiome of rats treated with CUMS, such as Shannon index increased and Simpson index decreased (P<0.01), while the abundance of Pseudomonadota and Bacteroidota increased in the hesperidin-treated group (P<0.05). CONCLUSION The mechanism responsible for the beneficial effects of hesperidin on depressive behavior in rats may be related to inhibition of the expressions of BDNF and 5-HT and preservation of the gut microbiota.
Animals ; Hesperidin/therapeutic use* ; Rats, Sprague-Dawley ; Depression/drug therapy* ; Male ; Stress, Psychological/drug therapy* ; Brain/metabolism* ; Brain-Derived Neurotrophic Factor/metabolism* ; Serotonin/metabolism* ; Gastrointestinal Microbiome/drug effects* ; Behavior, Animal/drug effects* ; Rats ; Brain-Gut Axis/drug effects* ; Chronic Disease ; Colon/drug effects*

OBJECTIVE: To investigate the therapeutic potential of pseudolaric acid B (PAB) on non-alcoholic fatty liver disease (NAFLD) and its underlying molecular mechanism in vitro and in vivo. METHODS: Eight-week-old male C57BL/6J mice (n=32) were fed either a normal chow diet (NCD) or a high-fat diet (HFD) for 8 weeks. The HFD mice were divided into 3 groups according to a simple random method, including HFD, PAB low-dose [10 mg/(kg·d), PAB-L], and PAB high-dose [20 mg/(kg·d), PAB-H] groups. After 8 weeks of treatment, glucose metabolism and insulin resistance were assessed by oral glucose tolerance test (OGTT) and insulin tolerance test (ITT). Biochemical assays were used to measure the serum and cellular levels of total cholesterol (TC), triglycerides (TG), aspartate aminotransferase (AST), alanine aminotransferase (ALT), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C). White adipose tissue (WAT), brown adipose tissue (BAT) and liver tissue were subjected to hematoxylin and eosin (H&E) staining or Oil Red O staining to observe the alterations in adipose tissue and liver injury. PharmMapper and DisGeNet were used to predict the NAFLD-related PAB targets. Peroxisome proliferator-activated receptor alpha (PPARα) pathway involvement was suggested by Kyoto Encyclopedia of Genes and Genomes (KEGG) and search tool Retrieval of Interacting Genes (STRING) analyses. Luciferase reporter assay, cellular thermal shift assay (CETSA), and drug affinity responsive target stability assay (DARTS) were conducted to confirm direct binding of PAB with PPARα. Molecular dynamics simulations were applied to further validate target engagement. RT-qPCR and Western blot were performed to assess the downstream genes and proteins expression, and validated by PPARα inhibitor MK886. RESULTS: PAB significantly reduced serum TC, TG, LDL-C, AST, and ALT levels, and increased HDL-C level in HFD mice (P<0.01). Target prediction analysis indicated a significant correlation between PAB and PPARα pathway. PAB direct target binding with PPARα was confirmed through luciferase reporter assay, CETSA, and DARTS (P<0.05 or P<0.01). The target engagement between PAB and PPARα protein was further confirmed by molecular dynamics simulations and the top 3 amino acid residues, LEU321, MET355, and PHE273 showed the most significant changes in mutational energy. Subsequently, PAB upregulated the genes expressions involved in lipid metabolism and mitochondrial biogenesis downstream of PPARα (P<0.05 or P<0.01). Significantly, the PPARα inhibitor MK886 effectively reversed the lipid-lowering and PPARα activation properties of PAB (P<0.05 or P<0.01). CONCLUSION PAB mitigates lipid accumulation, ameliorates liver damage, and improves mitochondrial biogenesis by binding with PPARα, thus presenting a potential candidate for pharmaceutical development in the treatment of NAFLD.
Animals ; PPAR alpha/metabolism* ; Non-alcoholic Fatty Liver Disease/pathology* ; Male ; Mice, Inbred C57BL ; Lipid Metabolism/drug effects* ; Diterpenes/therapeutic use* ; Organelle Biogenesis ; Diet, High-Fat ; Humans ; Mice ; Liver/metabolism* ; Insulin Resistance ; Mitochondria/metabolism* ; Molecular Docking Simulation

OBJECTIVE: The objective of our study was to evaluate the vaccine effectiveness (VE) of the pentavalent rotavirus vaccine (RV5) among < 5-year-old children in three provinces of China during 2020-2024 via a propensity score-matched test-negative case-control study. METHODS: Electronic health records and immunization information systems were used to obtain data on acute gastroenteritis (AGE) cases tested for rotavirus (RV) infection. RV-positive cases were propensity score matched with RV-negative controls for age, visit month, and province. RESULTS: The study included 27,472 children with AGE aged 8 weeks to 4 years at the time of AGE diagnosis; 7.98% (2,192) were RV-positive. The VE (95% confidence interval, CI) of 1-2 and 3 doses of RV5 against any medically attended RV infection (inpatient or outpatient) was 57.6% (39.8%, 70.2%) and 67.2% (60.3%, 72.9%), respectively. Among children who received the 3rd dose before turning 5 months of age, 3-dose VE decreased from 70.4% (53.9%, 81.1%) (< 5 months since the 3rd dose) to 63.0% (49.1%, 73.0%) (≥ 1 year since the 3rd dose). The three-dose VE rate was 69.4% (41.3%, 84.0%) for RVGE hospitalization and 57.5% (38.9%, 70.5%) for outpatient-only medically attended RVGE. CONCLUSION Three-dose RV5 VE against rotavirus gastroenteritis (RVGE) in children aged < 5 years was higher than 1-2-dose VE. Three-dose VE decreased with time since the 3rd dose in children who received the 3rd dose before turning five months of age, but remained above 60% for at least one year. VE was higher for RVGE hospitalizations than for medically attended outpatient visits.
Humans ; Rotavirus Vaccines/immunology* ; China/epidemiology* ; Case-Control Studies ; Child, Preschool ; Infant ; Rotavirus Infections/epidemiology* ; Male ; Propensity Score ; Female ; Vaccine Efficacy ; Gastroenteritis/virology* ; Vaccines, Attenuated ; Rotavirus

OBJECTIVE: Recombination events are common and serve as the primary driving force of diverse human adenovirus (HAdV), particularly in children with acute respiratory tract infections (ARIs). Therefore, continual monitoring of these events is essential for effective viral surveillance and control. METHODS: Respiratory specimens were collected from children with ARIs between January 2022 and December 2023. The penton base, hexon, and fiber genes were amplified from HAdV-positive specimens and sequenced to determine the virus type. In cases with inconsistent typing results, genes were cloned into the pGEM-T vector to detect recombination events. Metagenomic next-generation sequencing (mNGS) was performed to characterize the recombinant HAdV genomes. RESULTS: Among 6,771 specimens, 277 (4.09%, 277/6,771) were positvie for HAdV, of which 157 (56.68%, 157/277) were successfully typed, with HAdV-B3 being the dominant type (91.08%, 143/157), and 14 (5.05%, 14/277) exhibited inconsistent typing results, six of which belonged to species B. The penton base genes of these six specimens were classified as HAdV-B7, whereas their hexon and fiber genes were classified as HAdV-B3, resulting in a recombinant genotype designated P7H3F3, which closely resembled HAdV-B114. Additionally, a partial gene encoding L1 52/55 kD was identified, which originated from HAdV-B16. CONCLUSION A novel recombinant, P7H3F3, was identified, containing sequences derived from HAdV-B3 and HAdV-B7, which is similar to HAdV-B114, along with additional sequences from HAdV-B16.
Humans ; Adenoviruses, Human/isolation & purification* ; Respiratory Tract Infections/epidemiology* ; Child, Preschool ; Child ; Recombination, Genetic ; Male ; Beijing/epidemiology* ; Infant ; Female ; Phylogeny ; Adenovirus Infections, Human/epidemiology* ; Acute Disease ; Genome, Viral

Objective To summarize the acupoints and parameters commonly used in the treatment of vascular cognitive impairment(VCI)by electro-acupuncture(EA)through the visual data mining technique to provide a reference basis for clinical treatment.Methods The clinical studies of EA on the treatment of VCI were searched in CNKI,Wanfang,VIP,CBM,PubMed,Embase,Cochrane Library,web of science and other major databases.The literature is managed by Note Express and the database is established by Excel.The frequency of selected acupoints,frequency,meridian tropism,parameter frequency and frequency of used acupoints are counted.Factor analysis is carried out by SPSS 21.0 software.SPSS Modeler 18.3 software is used to analyze association rules and co-occurrence network,and the analysis results are visualized by Cytoscape 3.9.1 software.Results Finally,155 papers were included,containing 155 acupoint prescriptions and 157 parameter prescriptions.Acupoint prescriptions involved 100 acupoints with a total frequency of 856 times;parameter prescriptions involved 33 parameters with a total frequency of 788 times.Conclusion At present,there is a big difference between the clinical studies,and there is no recognized acupoint and parameter for EA treatment of VCI.By further summarizing the law of EA acupuncture point and parameter,the study has sorted out the law of commonly used acupoints,meridian tropism,compounding and parameter selection for EA treatment of VCI.It was concluded that the selection of acupoints mainly started from the three aspects of deficiency,phlegm and stasis,focusing on the combination of local and distal selection of acupoints,through the identification of internal organs and meridians,to achieve the simultaneous regulation of the heart,spleen and kidney,and to take into account both the symptoms and the root cause,and to play the roles of opening the orifices to wake up mind,calming mind and benefiting intellect,strengthening the spleen and tonifying the kidneys,and invigorating blood circulation to remove stasis.The parameters of EA are recommended to be sparse and dense wave,low frequency,as tolerated by the patient,30 minutes/times,1 time/day,5 times/week as the main combinations,which can provide a certain reference basis for clinical decision-making.