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.

Objective To determine the acetylation level of nucleophosmin(NPM)in female breast cancer and to discuss its function through mutation of modified lysine sites.To construct positive and negative NPM mutants on its acetylated lysine sites and to express them in breast cancer cells.Methods Acetylation level and acetylated lysine sites of NPM in three breast cancer tissues and para-carcinoma tissues were detected by acetylome technology;NPM mutants were constructed by site-directed mutagenesis PCR,specific PCR products were digested by DpnI and transformed into Escherichia coli(E.coli)to obtain specific plasmids for mutants;The accuracy of mutants were verified by double restriction enzyme digestion and sequencing;The mutants were expressed in BT-549 cells by transient transfection and verified by RT-PCR method.Protein expression and acetylation level of NPM were validated by Western blotting;Function of NPM acetylation was analyzed by proteomic detection and bioinformatic analysis.Results The 27th and 32nd lysine of NPM were highly acetylated in breast cancer tissues,which were 2.76 and 2.22 times higher than those in adjacent normal tissues,respectively;The NPM mutants showed the same molecular weight as that of wild type NPM and contained expected mutation sites;Corresponding NPM mRNA levels of BT-549 cells transfected with NPM mutants were significantly increased.With the increase of wild type NPM expression level,NPM acetylation level increased,while decreased after 27th lysine underwent negative mutation.NPM acetylation can significantly change the expression levels of 101 proteins in BT-549 cells,which are enriched in regulation of cellular macromolecule biosynthesis,DNA-template transcription,RNA biosynthesis and RNA metabolism process.Conclusion NPM is highly acetylated in breast cancer and can play a key role in cellular macromolecule biosynthesis,DNA-templated transcription,RNA biosynthesis and RNA metabolism process.

AIM To establish a UPLC-MS/MS method for the simultaneous content determination of liquiritin apioside,alibiflorin,swertiamarin,methyl gallate,benzoylpaeoniflorin,sweroside,6′-O-β-D-glucosylgentiopicroside,isoliquiritigenin,loganic acid,liquiritigenin,gallic acid,paeoniflorin,oxypaeoniflorin,gentiopicroside,glycyrrhizic acid,isoliquiritoside and liquiritin in Yangxue Ruanjian Capsules.METHODS The analysis was performed on a 40℃thermostatic Waters BEH C18column(2.1 mm×100 mm,1.7 μm),with the mobile phase comprising of 2 mmol/L ammonium acetate(containing 0.1%formic acid)-acetonitrile flowing at 0.3 mL/min in a gradient elution manner,and electron spray ionization source was adopted in negative ion scanning with multiple reaction monitoring mode.RESULTS Seventeen constituents showed good linear relationships within their own ranges(r>0.999 6),whose average recoveries were 91.33%-104.03%with the RSDs of 1.58%-3.50%.CONCLUSION This rapid,accurate and stable method can be used for the quality control of Yangxue Ruanjian Capsules.

AIM To investigate the effect of Wendan Decoction on nerve injury in a mouse model of sleep disorders and its mechanism.METHODS A mouse model of insomnia was established by the modified multiple platform sleep deprivation method.After successful modeling,the mice were randomly divided into the model group,the estazolam tablet group(0.15 mg/kg)and the low-dose and high-dose Wendan Decoction groups(12.5,50 g/kg),with 6 mice in each group,in contrast to the 6 mice of the control group.After 7 days of drug intervention,the mice had their changes of cerebral cortex,hippocampal CA1 area and hypothalamus observed by HE staining;their neuronal damage observed by Nissl staining;their levels of neurofilament light chain(NEFL),neuron-specific enolase(NSE),S100 calcium-binding protein B(S100B),tumor necrosis factor(TNF-α),interleukin-6(IL-6)and interleukin-1β(IL-1β)in brain tissue and serum detected by ELISA;their cerebral expression of glial fibrillary acidic protein(GFAP)detected by immunohistochemical method;and their cerebral expressions of GFAP,phosphorylated IκB kinase β(p-IKKβ)and phosphorylated nuclear transcription factor-κB(p-NF-κB)detected by Western blot.RESULTS Compared with the model group,the high-dose Wendan Decoction group displayed increased number of neurons,complete and neatly arranged structure;decreased number of neurons with nuclear shrinkage and deformation;increased Nissl bodies,decreased levels of NEFL,NSE,S100B,TNF-α,IL-6 and IL-1β in serum and brain tissue(P＜0.01);decreased cerebral expression of GFAP(P＜0.01);and decreased phosphorylation levels of cerebral p-IKKβ and p-NF-κB(P＜0.01).CONCLUSION Wendan Decoction can reduce the nerve damage and the expression of proinflammatory mediator in sleep disorders mice,and the mechanism may be related to the inhibited activation of IKKβ/NF-κB pathway.

OBJECTIVE To analyze the influential factors on trough concentration （cmin） and area under the drug concentration time curve （AUC） of voriconazole （VRZ） in pediatric patients with thalassemia undergoing hematopoietic stem cell transplantation （HSCT）. METHODS A total of 60 pediatric patients with thalassemia undergoing HSCT who used VRZ for prevention or treatment of invasive fungal infection were collected in our hospital from January 2021 to January 2024. The plasma concentration of VRZ was measured by high-performance liquid chromatography and the AUC was calculated. The factors affecting cmin and AUC of VRZ were analyzed using multiple linear regression. RESULTS A total of 120 cases of VRZ cmin in 60 pediatric patients was obtained and 27 cases of VRZ AUC in 26 pediatric patients were obtained. The median concentration of VRZ cmin was 0.31 mg/L； 46 cases had a cmin in 0.5-5 mg/L（ 38.33%）， 2 cases had a cmin＞5 mg/L（ 1.67%）， and 72 cases had a cmin＜0.5 mg/L. The median AUC of VRZ was 11.68 mg·h/L. The patient’s body weight， HSCT postoperative days， lymphocyte count， and combined use of phenytoin sodium， tacrolimus or cyclosporine had significant effects on VRZ cmin （P＜0.05）. Lymphocyte count and combined use of phenytoin sodium had significant effects on VRZ AUC （P＜0.05）. CONCLUSIONS The body weight， HSCT postoperative days， lymphocyte count， and combined use of phenytoin sodium， tacrolimus or cyclosporine are independent factors affecting VRZ cmin. Lymphocyte count and combined use of phenytoin sodium are independent factors affecting VRZ AUC.

The breakage pattern of unit particles during the production of oral solid dosage forms (OSD) is closely related to the quality of intermediate or final products. To accurately characterize the particles and study the evolution law of particle breakage, the Bonding model of the discrete element method (DEM) was used to investigate the breakage patterns of model parameters, particle shape and process conditions (loading mode and loading rate) on the dynamic breakage, force-time curve, breakage rate, maximum breakage size ratio and fracture strength of particles. The results showed that the particle breakage force was positively correlated with normal strength and bonded disk scale, negatively correlated with normal stiffness per unit area and tangential stiffness per unit area, and weakly correlated with tangential strength. The particle breakage rate was negatively correlated with the aspect ratio of the particles, and the maximum breakage size ratio was positively correlated with the aspect ratio of the particles; among the three loading modes, the breakage rate of compression breakage model was the largest, the breakage rate of shear breakage model was the second largest, and the breakage rate of wear breakage model was the smallest; the maximum breakage size ratio was positively correlated with the loading rate, the loading mode and the loading rate had no mutual influence on particle breakage rate, but had mutual influence on the maximum breakage size ratio. The research results will provide a theoretical basis for the shift of OSD from batch manufacturing to advanced manufacturing.

Objective To explore the relevant risk factors of H.pylori infection,and provide reference for prevention and treatment of H.pylori in this area,and further provide theoretical basis for the prevention and treatment of gastric cancer.Methods A total of 1200 residents in four districts of Haikou city were investigated by questionnaire and urea 14 C breath test by holistic stratified random sampling to calculate the population infection rate and analyze the risk factors of infection.Results The total infection rate was 32.5％,which was lower than the national H.pylori infection rate.No consumption of fruits and vegetables,no habit of washing hands before meals,and people with gastrointestinal symptoms,are independent risk factors of H.pylori infection.No consumption of pickled products is of great significance to prevent H.pylori infection.Conclusion The prevalence of H.pylori infection in the population of Haikou is lower than the national average,and H.pylori infection is closely related to the poor living habits of residents.

Ameloblastoma is a benign tumor characterized by locally invasive phenotypes,leading to facial bone destruction and a high recurrence rate.However,the mechanisms governing tumor initiation and recurrence are poorly understood.Here,we uncovered cellular landscapes and mechanisms that underlie tumor recurrence in ameloblastoma at single-cell resolution.Our results revealed that ameloblastoma exhibits five tumor subpopulations varying with respect to immune response(IR),bone remodeling(BR),tooth development(TD),epithelial development(ED),and cell cycle(CC)signatures.Of note,we found that CC ameloblastoma cells were endowed with stemness and contributed to tumor recurrence,which was dominated by the EZH2-mediated program.Targeting EZH2 effectively eliminated CC ameloblastoma cells and inhibited tumor growth in ameloblastoma patient-derived organoids.These data described the tumor subpopulation and clarified the identity,function,and regulatory mechanism of CC ameloblastoma cells,providing a potential therapeutic target for ameloblastoma.

Objective To investigate the effects of Simo decoction on duodenal microinflammation and NOD-like receptor thermal protein domain associated protein 3(NLRP3)/cysteinyl aspartate-specific proteinase-1(Caspase-1)/gasdermin D(GSDMD)signaling pathway in rats with functional dyspepsia(FD).Methods The FD model was established by multifactorial method.SD rats were randomly divided into normal group,model group(FD model),positive control group(gavage administration of 0.305 mg·kg-1 mosapride injection)and experimental-H,-M,-L groups(gavage administration of 5.62,2.81,1.40 g·kg-1 Simo decoction).Small intestinal advancement rate and gastric emptying rate was determined;the levels of interleukin(IL)-1 β and IL-18 in serum were determined by enzyme linked immunosorbent assay(ELISA);the protein expression of NLRP3 and GSDMD in duodenal tissue was detected by Western blotting.Results The gastric emptying rates of normal,model,positive control and experimental-H,-M,-Lgroupswere(58.34±5.72)％,(29.16±8.37)％,(48.77±6.10)％,(48.35±6.04)％,(48.20±3.49)％and(39.24±4.20)％;the small intestinal propulsion rates were(82.01±7.55)％,(41.95±9.53)％,(64.61±10.18)％,(75.04±9.76)％,(60.58±7.13)％and(45.89±7.40)％;serum IL-1 β expression were(12.86±0.88),(43.73±4.60),(18.84±0.86),(24.61±1.57),(19.14±0.77)and(29.04±0.72)pg·mL-1;IL-18 expressions were(95.00±3.74),(170.60±8.78),(108.50±3.05),(118.90±3.45),(99.90±8.70)and(141.00±3.71)pg·mL-1;the relative expression levels of NLRP3 proteins were 0.32±0.02,0.84±0.05,0.42±0.03,0.48±0.02,0.61±0.04 and 0.62±0.05;the relative expression levels of GSDMD proteins were 0.34±0.05,0.93±0.06,0.35±0.03,0.52±0.02,0.53±0.06 and 0.55±0.05,respectively.Compared with the normal group,the above indexes in the model group have statistical significance;compared with the model group,the above indexes in the experimental-H group and the positive control group also have statistical significance(P＜0.01 or P＜0.05).Conclusion Simo decoction can effectively improve the general condition and duodenal microinflammation in FD rats,and the mechanism may be related to the inhibition of duodenal NLRP3/Caspase-1/GSDMD signaling pathway.

The assessment of adverse drug events is an important basis for clinical safety evaluation and post-marketing risk control of drugs,and its causality assessment is gaining increasing attention.The existing methods for assessing the causal relationship between drugs and the occurrence of adverse reactions can be broadly classified into three categories:global introspective methods,standardized methods,and probabilistic methods.At present,there is no systematic introduction of the operational details of the various methods in the domestic literature.This paper compares representative causality assessment methods in terms of definition and concept,methodological steps,industry evaluation and advantages and disadvantages,clarifies the basic process of determining the causality of adverse drug reactions,and discusses how to further improve the adverse drug reaction monitoring and evaluation system,with a view to providing a reference for drug development and pharmacovigilance work in China.