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 screen for ferroptosis-related differentially expressed genes(DEGs)of epidermal growth factor receptor(EGFR)-tyrosine kinase inhibitors(TKIs)resistance in non-small cell lung cancer(NSCLC).Methods The gene sequencing dataset GSE117846 of NSCLC EGFR-TKIs resistant cells was se-lected from the Gene Expression Omnibus data base(GEO)and screened for DEGs with P＜0.05 and | log2 FC |1.Ferroptosis-related genes were collected using the FerrDb database and jvenn was used to intersected the DEGs screened from GSE117846 dataset with the ferroptosis-related genes obtained from FerrDb database.GO function and KEGG pathway enrichment analysis of intersection genes were performed,and protein-pro-tein interaction(PPI)network was drawn.The score of intersection genes was calculated by using Cytohubba plug-in in Cytoscape software,and the top 10 genes were used for Hub genes screening.ULCAN and GEPIA2 databases were used to analyze the expression of Hub genes in NSCLC and its effect on the survival prognosis of patients.Real-time fluorescence quantitative PCR(qPCR)was used to detect the relative expression levels of Hub gene mRNA in NSCLC patients'cancer tissues,adjacent tissues and in vitro cells to verify the results of bioinformatics analysis.Results A total of 60 ferroptosis-related DEGs of EGFR-TKIs resistance in NSCLC were screened out,including 30 up-regulated genes and 30 down-regulated genes.The 60 genes were mainly enriched in P53 signaling pathway,ferroptosis pathway and FoxO signaling pathway.There were 57 nodes and 99 edges in the PPI network,with an average clustering coefficient of 0.377 and PPI enrichment P＜0.01.The Hub gene screened out by Cytohubba plug-in was tumor protein P63(TP63).ULCAN and GE-PIA2 database analysis showed that the expression of TP63 in lung adenocarcinoma tissue was significantly lower than that in normal tissue,while the expression of TP63 in lung squamous cell carcinoma tissue was sig-nificantly higher than that in normal tissue,and the differences were statistically significant(P＜0.05).In pa-tients with lung adenocarcinoma,there was no significant difference in the survival prognosis between TP63 high and low expression groups(P＞0.05),while in patients with lung squamous cell carcinoma,the survival prognosis of TP63 low expression group was better,and the difference was statistically significant(P＜0.05).QPCR showed that TP63 mRNA highly expressed in lung squamous cell carcinoma tissue and lowly expressed in lung adenocarcinoma tissue compared with adjacent tissues(P＜0.05).The expression of TP63 mRNA was down-regulated in gefitinib-resistant PC9/GR cells(P＜0.05),which was consistent with the re-sults of bioinformatics analysis.Conclusion TP63 may be an important gene linking NSCLC EGFR-TKIs re-sistance to ferroptosis.

OBJECTIVE: To explore the mechanism of electroacupuncture (EA) in promoting recovery of the facial function with the involvement of autophagy, glial cell line-derived neurotrophic factor (GDNF), and phosphatidylinositol-3-kinase (PI3K)/mammalian target of rapamycin (mTOR) signaling pathway. METHODS: Seventy-two male Sprague-Dawley rats were randomly allocated into the control, sham-operated, facial nerve injury (FNI), EA, EA+3-methyladenine (3-MA), and EA+GDNF antagonist groups using a random number table, with 12 rats in each group. An FNI rat model was established with facial nerve crushing method. EA intervention was conducted at Dicang (ST 4), Jiache (ST 6), Yifeng (SJ 17), and Hegu (LI 4) acupoints for 2 weeks. The Simone's 10-Point Scale was utilized to monitor the recovery of facial function. The histopathological evaluation of facial nerves was performed using hematoxylin-eosin (HE) staining. The levels of Beclin-1, light chain 3 (LC3), and P62 were detected by immunohistochemistry (IHC), immunofluorescence, and reverse transcription-polymerase chain reaction, respectively. Additionally, IHC was also used to detect the levels of GDNF, Rai, PI3K, and mTOR. RESULTS: The facial functional scores were significantly increased in the EA group than the FNI group (P<0.05 or P<0.01). HE staining showed nerve axons and myelin sheaths, which were destroyed immediately after the injury, were recovered with EA treatment. The expressions of Beclin-1 and LC3 were significantly elevated and the expression of P62 was markedly reduced in FNI rats (P<0.01); however, EA treatment reversed these abnormal changes (P<0.01). Meanwhile, EA stimulation significantly increased the levels of GDNF, Rai, PI3K, and mTOR (P<0.01). After exogenous administration with autophagy inhibitor 3-MA or GDNF antagonist, the repair effect of EA on facial function was attenuated (P<0.05 or P<0.01). CONCLUSIONS EA could promote the recovery of facial function and repair the facial nerve damages in a rat model of FNI. EA may exert this neuroreparative effect through mediating the release of GDNF, activating the PI3K/mTOR signaling pathway, and further regulating the autophagy of facial nerves.
Rats ; Male ; Animals ; Rats, Sprague-Dawley ; Electroacupuncture ; Phosphatidylinositol 3-Kinase/metabolism* ; Facial Nerve Injuries/therapy* ; Phosphatidylinositol 3-Kinases/metabolism* ; Beclin-1 ; Glial Cell Line-Derived Neurotrophic Factor ; Signal Transduction ; TOR Serine-Threonine Kinases/metabolism* ; Autophagy ; Mammals/metabolism*

Objective: To explore incidence trend of hepatitis C in Chifeng City, Inner Mongolia Autonomous Region from 2008 to 2022, so as to provide the basis for formulating prevention and control measures for hepatitis C. Methods: Data of reported hepatitis C cases in Chifeng City from 2008 to 2022 was collected through the Infectious Disease Information Reporting Management System. Trends in incidence of hepatitis C were analyzed using annual percent change (APC) and average annual percent change (AAPC). Impact of age, period and birth cohort on the risk of developing hepatitis C were analyzed by an age-period-cohort model. Results: The annual average reported incidence rate of hepatitis C in Chifeng City was 59.13/105 from 2008 to 2022. The incidence showed an upward trend from 2008 to 2018 (APC=9.405%, P<0.05) and a downward trend from 2018 to 2022 (APC=-17.475%, P<0.05), but the overall trend was not statistically significant (AAPC=0.937%, P>0.05). The age-period-cohort model analysis showed that the incidence risks of hepatitis C in the residents aged 0 to 4 years and 45 to 84 years were higher than those in the residents aged 40 to 44 years (the control group). The incidence risk of hepatitis C increased with age from 40 to 79 years. Compared with 2008-2012, the incidence risk of hepatitis C showed an increasing trend followed by a decline in 2008-2022. The incidence risk was higher in 2013-2017 and lower in 2018-2022 than in 2008-2012. The incidence risk of hepatitis C showed an increasing trend followed by a decreasing trend by using the birth cohort from 1968 to 1972 as the control. The birth cohort from 1953 to 1977 had a higher incidence risk of hepatitis C than other birth cohorts. Conclusions The overall incidence of hepatitis C in Chifeng City from 2008 to 2022 appeared a tendency towards a decline, and the incidence risk increased with age. Screening and health education for the elderly and high-risk birth cohorts should be strengthened.

Objective To investigate the impact of emodin(EM)on vascular endothelial cell injury in rats with diabetes macroangiopathy by regulating hypoxia inducible factor-1α(HIF-1α)/vascular endothelial growth factor(VEGF)signaling pathway.Methods SD rats were divided into blank group and modeling group,the rats in the modeling group were fed with high fat and high sugar combined with N-nitro-L-arginine methyl ester to build the diabetes macroangiopathy model,and the blank group was fed with ordinary diet.The vascular endothelial cells successfully isolated from the thoracic aorta of rats in blank group and modeling group were named control group and model group,respectively.The vascular endothelial cells in the modeling group were divided into model group,dimethyloxallyl glycine(DMOG)group(10 μmol·L-1DMOG),combined group(80 mg·L-1EM+10 μmol·L-1 DMOG)and experimental-L,-M,-H groups(20,40,80 mg·L-1 EM).The apoptosis of rat vascular endothelial cells was detected by flow cytometry;Western blot was applied to detect the expression of HIF-1αand VEGF proteins in rat vascular endothelial cells.Results The apoptosis rates of vascular endothelial cells in experimental-M,-H groups,DMOG group,combined group,model group and control group were(10.18±0.36)％,(6.28±0.20)％,(24.96±1.18)％,(12.36±0.49)％,(18.76±0.68)％and(4.59±0.26)％;HIF-1α protein levels were 0.96±0.07,0.78±0.06,2.03±0.12,1.05±0.13,1.58±0.12 and 0.69±0.05;VEGF protein levels were 0.59±0.05,0.23±0.02,0.98±0.06,0.63±0.04,0.86±0.07 and 0.11±0.01.The above indexes in the model group were compared with the control,DMOG,experimental-M and experimental-H groups,and the above indexes in the combined group were compared with the experimental-H group,and the differences were statistically significant(all P＜0.05).Conclusion EM may inhibit HIF-1α/VEGF pathway to improve vascular endothelial cell injury in rats with diabetes macroangiopathy.

Objective To evaluate the bioequivalence and safety of two pyrazinamide tablets in healthy Chinese subjects.Methods An open,randomized,single-dose,two-sequence,two-cycle,double-cross trial design was used.All 48 healthy subjects(24 in fasting and 24 in fed trial)were randomized to receive a single oral dose of a 0.5 g pyrazinamide tablet(test or reference)per cycle.The plasma concentration of the drug was determined by liquid chromatography coupled to tandem mass spectrometry method.The pharmacokinetic parameters were calculated by WinNonlin v8.2,and the bioequivalence was evaluated by SAS 9.4.Results In the fasting group,the Cmax of the test and reference preparation of pyrazinamide tablets were(13.28±2.82)and(12.88±4.49)μg·mL-1,the AUC0-t were(139.17±26.58)and(138.63±28.92)h·μg·mL-1,the AUC0-∞ were(148.96±33.65)and(148.71±36.97)h·μg·mL-1 respectively.In the fed group,the Cmax of the test and reference preparation of pyrazinamide tablets were(11.89±1.96)and(11.99±1.92)μg·mL-1,the AUC0-t were(138.22±37.21)and(141.68±25.80)h·μg·mL-1,the AUC0-∞ were(152.20±32.41)and(151.04±28.05)h·μg·mL-,respectively.The 90％confidence intervals of Cmax,AUC0-t and AUC0-∞ geometric mean ratios of the test and reference preparation were all within 80.00％to 125.00％.The incidence of adverse events was 16.70％for both the test and reference preparation in the fasting group and 8.30％for both the test and reference preparation in the fed group,all of which were mild in severity.Conclusion The test and reference preparation of pyrazinamide tablets were bioequivalent,safe and well tolerated in healthy Chinese subjects under fasting and fed conditions.

Objective Combination immunotherapy strategies targeting OX40,a co-stimulatory molecule that can enhance antitumor immunity by modulating the proliferation,differentiation,and effector function of tumor-infiltrating T cells,have attracted much attention for their excellent therapeutic effects.In this study,we aimed to evaluate the antitumor efficacy of combined anti-OX40 and hepatitis B core virus-like particles(HBc VLPs)therapy using a mouse colon cancer model. Methods Humanized B-hOX40 mice were injected subcutaneously with MC38 colon tumor cells and treated with HBc VLPs+anti-hOX40 antibody.Tumor growth was monitored.Flow cytometric analysis was performed to evaluate the populations of T cell subsets in the tumors. Results The combination of anti-OX40 with HBc VLPs resulted in a significant delay in tumor growth,suggesting that a potent antitumor immunity was induced by the combination therapy.Further studies revealed that HBc VLPs+anti-OX40 treatment induced a significant increase in effector T cells(Teffs)and a significant decrease in regulatory T cells(Tregs)in the tumor microenvironment(TME),which accounted for the synergistic antitumor effect of anti-OX40 in combination with HBc VLPs. Conclusion Combination therapy of anti-hOX40 and HBc VLPs provides synergistic antitumor activity in colon cancer-bearing mice,which may represent a potential design strategy for cancer immunotherapy.

Objective:To investigate the clinical significance of tumor budding as an indicator of postoperative distant organ metastasis after radical gastrectomy in elderly patients diagnosed with gastric cancer.Methods:The clinical and pathological data of 124 elderly patients who experienced metastasis after undergoing radical gastrectomy were retrospectively analyzed.The analysis was conducted from March 2015 to June 2022, focusing on the clinicopathological factors that influenced the occurrence of postoperative distant metastasis in these patients.Tumor budding in gastric cancer tissues was assessed using hematoxylin-eosin staining, and its clinical significance was analyzed.Results:The tumor budding grade of gastric cancer tissues showed a significant correlation with vascular invasion( χ2=6.731, P=0.009), the number of lymph node metastases( rs=0.481, P<0.001), and the time of distant metastasis( rs=-0.450, P<0.001).In the univariate analysis, factors such as tumor budding grade, tumor size, vascular invasion, postoperative chemotherapy, cancerous nodule, preoperative serum carbohydrate antigen 125, and the number of lymph node metastases were found to influence distant metastasis-free survival after radical gastrectomy in elderly patients(all P<0.05).The multifactorial analysis also indicated that tumour outgrowth grade was an important independent prognostic factor for postoperative distant metastasis in elderly gastric cancer patients( HR=3.731, P<0.001). Conclusions:The findings of this study indicate that tumor budding may serve as a potential marker for predicting distant organ metastasis in elderly patients who have undergone radical gastrectomy.This discovery holds significant clinical implications.

【Objective】 To develop a clinical prediction model based on ⁶⁸Ga-prostate-specific membrane antigen-11 (⁶⁸Ga-PSMA-11), positron emission tomography/computed tomography (PET/CT) and multiparametric magnetic resonance imaging (mpMRI) parameters to stratify prostate cancer patients undergoing targeted biopsy, so as to avoid unnecessary systematic biopsy. 【Methods】 A total of 96 clinically significant prostate cancer (csPCa) patients who underwent ⁶⁸Ga-PSMA-11 PET/CT and mpMRI prior to prostate targeted biopsy with systematic biopsy during Jan.2020 and Feb.2023 in Nanjing Drum Tower Hospital were retrospectively analyzed.By univariate and multivariate logistic regression analyses, maximum standard uptake value (SUVmax) in ⁶⁸Ga-PSMA-11 PET/CT and minimum apparent diffusion coefficien (ADCmin) in mpMRI, as well as clinical parameters were evaluated to identify the independent predictors correlative with the effective diagnosis of targeted biopsy, and a clinical prediction model was constructed. 【Results】 Multivariate logistic regression analysis showed that SUVmax (OR=0.878, 95%CI: 0.804-0.959, P=0.004) and ADCmin (OR=1.005, 95%CI:1.001-1.010, P=0.027) were independent predictors of the effective diagnosis of targeted biopsy alone.The sensitivity, specificity, accuracy and area under the receiver operator characteristic curve (AUC) of the model were 0.80, 0.80, 0.83 and 0.84, respectively. 【Conclusion】 The clinical prediction model based on ⁶⁸Ga-PSMA-11 PET/CT and mpMRI parameters is helpful to improve the effective diagnosis of targeted biopsy alone, and has practical value to stratify patients with csPCa so as to safely avoid systematic biopsy and effectively balance the benefits and risks.

Digital intraoral scanning is a hot topic in the field of oral digital technology.In recent years,digital intra-oral scanning has gradually become the mainstream technology in orthodontics,prosthodontics,and implant dentistry.The precision of digital intraoral scanning and the accuracy and stitching of data collection are the keys to the success of the impression.However,the operators are less familiar with the intraoral scanning characteristics,imaging process-ing,operator scanning method,oral tissue specificity of the scanned object,and restoration design.Thus far,no unified standard and consensus on digital intraoral scanning technology has been achieved at home or abroad.To deal with the problems encountered in oral scanning and improve the quality of digital scanning,we collected common expert opin-ions and sought to expound the causes of scanning errors and countermeasures by summarizing the existing evidence.We also describe the scanning strategies under different oral impression requirements.The expert consensus is that due to various factors affecting the accuracy of digital intraoral scanning and the reproducibility of scanned images,adopting the correct scanning trajectory can shorten clinical operation time and improve scanning accuracy.The scanning trajec-tories mainly include the E-shaped,segmented,and S-shaped methods.When performing fixed denture restoration,it is recommended to first scan the abutment and adjacent teeth.When performing fixed denture restoration,it is recommend-ed to scan the abutment and adjacent teeth first.Then the cavity in the abutment area is excavated.Lastly,the cavity gap was scanned after completing the abutment preparation.This method not only meets clinical needs but also achieves the most reliable accuracy.When performing full denture restoration in edentulous jaws,setting markers on the mucosal tissue at the bottom of the alveolar ridge,simultaneously capturing images of the vestibular area,using different types of scanning paths such as Z-shaped,S-shaped,buccal-palatal and palatal-buccal pathways,segmented scanning of dental arches,and other strategies can reduce scanning errors and improve image stitching and overlap.For implant restora-tion,when a single crown restoration is supported by implants and a small span upper structure restoration,it is recom-mended to first pre-scan the required dental arch.Then the cavity in the abutment area is excavated.Lastly,scanning the cavity gap after installing the implant scanning rod.When repairing a bone level implant crown,an improved indi-rect scanning method can be used.The scanning process includes three steps:First,the temporary restoration,adjacent teeth,and gingival tissue in the mouth are scanned;second,the entire dental arch is scanned after installing a standard scanning rod on the implant;and third,the temporary restoration outside the mouth is scanned to obtain the three-di-mensional shape of the gingival contour of the implant neck,thereby increasing the stability of soft tissue scanning around the implant and improving scanning restoration.For dental implant fixed bridge repair with missing teeth,the mobility of the mucosa increases the difficulty of scanning,making it difficult for scanners to distinguish scanning rods of the same shape and size,which can easily cause image stacking errors.Higher accuracy of digital implant impres-sions can be achieved by changing the geometric shape of the scanning rods to change the optical curvature radius.The consensus confirms that as the range of scanned dental arches and the number of data concatenations increases,the scanning accuracy decreases accordingly,especially when performing full mouth implant restoration impressions.The difficulty of image stitching processing can easily be increased by the presence of unstable and uneven mucosal mor-phology inside the mouth and the lack of relatively obvious and fixed reference objects,which results in insufficient ac-curacy.When designing restorations of this type,it is advisable to carefully choose digital intraoral scanning methods to obtain model data.It is not recommended to use digital impressions when there are more than five missing teeth.