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 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.

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 The purpose of this study was to investigate the bacterial communities of biting midges and ticks collected from three sites in the Poyang Lake area,namely,Qunlu Practice Base,Peach Blossom Garden,and Huangtong Animal Husbandry,and whether vectors carry any bacterial pathogens that may cause diseases to humans,to provide scientific basis for prospective pathogen discovery and disease prevention and control. Methods Using a metataxonomics approach in concert with full-length 16S rRNA gene sequencing and operational phylogenetic unit(OPU)analysis,we characterized the species-level microbial community structure of two important vector species,biting midges and ticks,including 33 arthropod samples comprising 3,885 individuals,collected around Poyang Lake. Results A total of 662 OPUs were classified in biting midges,including 195 known species and 373 potentially new species,and 618 OPUs were classified in ticks,including 217 known species and 326 potentially new species.Surprisingly,OPUs with potentially pathogenicity were detected in both arthropod vectors,with 66 known species of biting midges reported to carry potential pathogens,including Asaia lannensis and Rickettsia bellii,compared to 50 in ticks,such as Acinetobacter lwoffii and Staphylococcus sciuri.We found that Proteobacteria was the most dominant group in both midges and ticks.Furthermore,the outcomes demonstrated that the microbiota of midges and ticks tend to be governed by a few highly abundant bacteria.Pantoea sp7 was predominant in biting midges,while Coxiella sp1 was enriched in ticks.Meanwhile,Coxiella spp.,which may be essential for the survival of Haemaphysalis longicornis Neumann,were detected in all tick samples.The identification of dominant species and pathogens of biting midges and ticks in this study serves to broaden our knowledge associated to microbes of arthropod vectors. Conclusion Biting midges and ticks carry large numbers of known and potentially novel bacteria,and carry a wide range of potentially pathogenic bacteria,which may pose a risk of infection to humans and animals.The microbial communities of midges and ticks tend to be dominated by a few highly abundant bacteria.

Objective Little is known about the association between whole-blood nicotinamide adenine dinucleotide(NAD+)levels and nabothian cysts.This study aimed to assess the association between NAD+levels and nabothian cysts in healthy Chinese women. Methods Multivariate logistic regression analysis was performed to analyze the association between NAD+levels and nabothian cysts. Results The mean age was 43.0±11.5 years,and the mean level of NAD+was 31.3±5.3 μmol/L.Nabothian cysts occurred in 184(27.7%)participants,with single and multiple cysts in 100(15.0%)and 84(12.6%)participants,respectively.The total nabothian cyst prevalence gradually decreased from 37.4%to 21.6%from Q1 to Q4 of NAD+and the prevalence of single and multiple nabothian cysts also decreased across the NAD+quartiles.As compared with the highest NAD+quartile(≥34.4 μmol/L),the adjusted odds ratios with 95%confidence interval of the NAD+Q1 was 1.89(1.14-3.14)for total nabothian cysts.The risk of total and single nabothian cysts linearly decreased with increasing NAD+levels,while the risk of multiple nabothian cysts decreased more rapidly at NAD+levels of 28.0 to 35.0 μmol/L. Conclusion:Low NAD+levels were associated with an increased risk of total and multiple nabothian cysts.

Aim To investigate the effects of Radix Angelica Sinensis and Radix Hedysari ultrafiltration(RAS-RH)on oxidative stress and inflammatory injury of human umbilical vein endothelial cells(HUVECs)induced by ionizing radiation.Methods The model of HUVECs damage induced by 6 Gy X-rays was estab-lished.HUVECs were treated with different concentra-tions of RAS-RH(100,200,400 μg·L-1).The proliferative activity of HUVECs was detected by CCK-8 method,the structural changes of mitochondria were observed by transmission electron microscope,the level of ROS was detected by DCFH-DA probe,the change of intracellular mitochondrial membrane potential was detected by JC-1 kit,and the apoptosis and cycle were detected by flow cytometry.The contents of IL-6 and TNF-α in cells were detected by ELISA.The activities of MDA,CAT,SOD and GSH-PX were detected by biochemical kit.The gene expression levels of Nrf2,HO-1,NF-κB,eNOS and IL-6 were detected by qRT-PCR,and the expression levels of Nrf2,HO-1,eNOS,NF-κB,p-NF-κB and IL-6 protein were detected by Western blot.Results Compared with the model group,RAS-RH could increase the activity of HUVECs induced by ionizing radiation,decrease the rate of ap-optosis,decrease the level of intracellular ROS,re-duce the injury of intracellular mitochondria,increase the level of mitochondrial membrane potential,promote the expression of Nrf2,HO-1 and eNOS,and inhibit the expression of NF-κB and IL-6.Conclusions RAS-RH has anti-radiation,antioxidant and anti-in-flammatory effects,which may reduce the oxidative stress and inflammatory damage of HUVECs induced by ionizing radiation by activating the activity of Nrf2/HO-1 signal pathway,thus promoting the activity of cell proliferation.