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.

In this study, fluvoxamine maleate sustained-release pellet system tablets were prepared and were used to evaluate their release behaviors in vitro. Fluvoxamine maleate pellets were prepared using centrifugal-spherization method and coated by fluidized bed as bottom-spray. The multi-unit sustained-release pellets and appropriate excipients for prescription volumes were mixed uniformly and then compressed to tablets. Screening and determining the optimal formulation of drug loaded pellets through L8 (2⁴) Taguchi experiment. Using Minitab software to design a DOE experiment with 2⁴ partial factors, including material temperature, fan speed, atomization pressure, and spray rate to optimize the bottom spray coating process. Taking monostearate glycerol ester with a particle size of 24-40 mesh as the main diluent for tableting to relieve the delamination phenomenon between pellets and excipients during tablet pressing and reduce mechanical damage to the coating film. By examining the powder fluidity indexes such as angle of repose, bulk density, tapped density, and Hausner ratio of mixed particles, it was found that the flowability and compressibility are good and suitable for direct compression. Evaluate the basic properties of the sustained-release tablets, investigate the in vitro release behavior and study the release mechanism. The results of in vitro release test showed that the self-made sustained-release tablets could disintegrate into independent pellet units in phosphate buffer at pH 6.8 and release slowly within 24 h, which conformed to the first-order drug release model. The fluvoxamine maleate sustained-release pellet system tablets meet the requirements of preparation design and has a great commercial prospect.

Objective:To discuss the effect of royal jelly acid(10-HDA)on the proliferation and migration of the human colon cancer SW620 cells based on the network pharmacology,and to clarify its related molecular mechanism.Methods:The active ingredients such as 10-HDA and their corresponding targets were retrieved by using the keyword"royal jelly"from the Traditiomal Chinese Medicine Systems Pharmacology(TMSCP)Database and the Traditiomal Chinese Medicine Integrated Database(TCMID);the small molecule targets were predicted by the Swiss Target Prediction Database.The GeneCards Database and the Online Mendelian Inheritance in Man(OMIM)Database were used to obtain the targets with the keyword"Colon Cancer";the protein-protein interaction(PPI)network was constructed by using the String Database and Cytoscape 3.8.0 Software to screen the core targets;the Gene Ontology(GO)function enrichment analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG)signaling pathway enrichment analysis were analyzed by Metascape Database;the specific ingredient 10-HDA was screened for the in vitro activity experiments.The human colon cancer SW620 cells with good growth status were divided into control group and different doses(1,5,10,15,and 20 mmol·L-1)of 10-HDA groups.The viabilities of the cells in various groups were detected by MTT method and the survival rates of the cells were calculated.The SW620 cells were divided into control group,low dose(5 mmol·L-1)of 10-HDA group,middle dose(10 mmol·L-1)of 10-HDA group,and high dose(15 mmol·L-1)of 10-HDA group;Hoechst33342 staining method was used to observe the morphology of the cells in various groups;cell scratch test was used to detect the scratch healing rates of the cells in various groups;flow cytometry was used to detect the percentages of the cells at different cell cycles in various groups;biochemical method was used to detect the activities of total antioxidant capacity(T-AOC)and superoxide dismutase(SOD)in the cells in various groups;Western blotting method was used to detect the expression levels of B-cell lymphoma 2(Bcl-2),Bcl-2-associated X protein(Bax),cysteine-containing aspartate proteolytic enzyme-3(Caspase-3),cysteine-containing aspartate proteolytic enzyme-9(Caspase-9),glycogen synthase kinase 3β(GSK3β),β-catenin,and cyclin D1 proteins in the cells in various groups.Results:Six active ingredients of royal jelly were screened out by the TCMSP Database,and 28 core targets of 10-HDA in the treatment of colon cancer were obtained.The GO function enrichment analysis mainly included the signaling pathways such as cell proliferation and apoptosis.The KEGG signaling pathway enrichment analysis included the cell cycle,prostate cancer,cell senescence,and p53 signaling pathways;the GSK3β/β-catenin signaling pathway was closely related to the cell cycle.Compared with control group,the viabilities of the cells in 5,10,15,and 20 mmol·L-110-HDA groups were decreased in a dose-dependent manner(P<0.05 or P<0.01),the numbers of apoptotic cells in different doses of 10-HDA groups were significantly increased,and the scratch healing rates of the cells were significantly decreased(P<0.05 or P<0.01);the percentages of the cells at S phase in middle and high doses of 10-HDA groups were significantly increased(P<0.05 or P<0.01),the activities of T-AOC and SOD in the cells in different doses of 10-HDA groups were significantly decreased(P<0.05 or P<0.01).Compared with control group,the expression level of Bcl-2 protein in the cells in low dose of 10-HDA group was significantly decreased(P<0.01),and the expression level of GSK3β protein was significantly increased(P<0.05);compared with control group,the expression levels of Bax,Caspase-3,Caspase-9,and GSK3β proteins in the cells in middle and high doses of 10-HDA groups were significantly increased(P<0.05 or P<0.01),and the expression levels of Bcl-2,β-catenin,and CyclinD1 proteins were significantly decreased(P<0.01).Conclusion:10-HDA can significantly inhibit the proliferation and migration of the colon cancer cells and promote the apoptosis and oxidation levels of the colon cancer cells,and its mechanism may be related to the activation of the GSK3β/β-catenin signaling pathway.

Immunoassays are widely used in medicine, food, environment and other fields due to having the advantages of simpleness, rapidness and accuracy. Combining immunoassays with nanomaterials can improve the performance of immunoassays. Compared with traditional nanomaterials, upconversion nanoparticles (UCNPs) have excellent optical properties such as good photostability, long luminescence lifetime and narrow and tunable emission bands, which can significantly reduce background noise and improve analytical sensitivity when combined with immunoassay. This paper briefly introduces the luminescence mechanism of UCNPs, summarizes the synthesis and surface modification methods of UCNPs. And then 5 UCNPs-based immunoassay techniques, namely, fluorescence resonance energy transfer, inner filter effect, magnetic separation technique, upconversion-linked immunosorbent assay and upconversion immunochromatography, are discussed in detail. These sensing protocols of UCNPs-based immunoassays have been successfully utilized to detect various targets, including small molecules, macromolecules, and pathogens, all of which closely related to food safety, human health, and environmental pollution. Finally, the challenges and prospects of this technique are summarized and prospected. Although the UCNPs immunoassays based on antibodies and antigens have made great progress, most of the research is still in the stage of laboratory, and there is a long way to go to realize its social applications. There is a series of challenges need to be overcome. (1) Designing excellent water soluble and dispersive upconversion nanomaterials is needed. Hydrophilic ligands are bound to smaller upconversion nanoparticles and removing hydrophobic surface ligands are the most widely used methods to improve solubility and dispersity. (2) Multi-detection technology platforms and multi-mode simultaneous detection platforms have great potential, which will improve the efficiency of point of care detection. (3) The researchers also need to focus on some important problems. For examples, the upconversion luminescence efficiency of UCNPs is difficult to maintain, the synthesis method is complex, and the surface modification degree and functionalization are difficult to control.

Objective To understand the current status and trends of research on the TCM treatment for stable phase of chronic obstructive pulmonary disease(COPD);To provide references for relevant research.Methods Literature about TCM treatment for stable phase of COPD was retrieved from China National Knowledge Infrastructure,Wanfang Data,VIP Information Chinese Journal Service Platform,and SinoMed from the establishment of the databases to Sep 1,2022.NoteExpress 3.4 was used to sort out the basic data of papers.Excel 2016 was employed to count first authors,syndrome type,prescription and draw a run chart of publication,determine the number of journals in the core area according to Bradford law.Core authors statistically were analyzed according to Price law.Author collaboration network and keyword co-occurrence analysis were conducted using VOSviewer 1.6.18.CiteSpace 5.3.R4 was exploited to construct institutional collaboration network and study burst terms,and knowledge map was drawn.Results A total of 3 360 articles were included,involving 445 journals,with 2 691 first authors.The overall number of publications in this field showed an increasing trend,with clinical research being the main research type.There were 21 journals in the core region and the most frequently published journal was New Chinese Medicine.There were 125 core authors,with Li Zhuying and Li Jiansheng posting the most articles.Author collaboration network analysis showed 10 major research teams and the largest of which was Li Jiansheng's team.There were 1 451 institutions,mainly were universities and affiliated hospitals.There were 62 types of syndromes in the stable phase of COPD,the most common of which was the syndrome of qi deficiency of lung and spleen.There were 541 kinds of prescriptions in total,and the most commonly used was Bufei Decoction.Keyword co-occurrence analysis showed 8 subjects,and the high-frequency keywords included lung function,clinical efficacy,quality of life,clinical observation and TCM treatment.22 burst terms were obtained,with Budesonide Fumotro,six-word songs,Yupingfeng Powder and inflammatory factors highly concerned at present.Conclusion The research fever of TCM treatment for COPD in stable period shows an increasing trend,and clinical research accounts for the largest proportion,but the general quality is not high,and basic research is relatively lacking.The research focuses on the inhibition of airway inflammation and immune regulation,and lung function and quality of life are the most commonly used evaluation indicators.

This study design of specific identification primers for the ITS2 sequence of F. ussuriensis. The reaction system and conditions were optimized, and PCR-nucleic acid test strips were constructed to realize the visual detection of F. ussuriensis Bark. Through molecular cloning and sequencing technology, we constructed a positive control for F. ussuriensis DNA and formulated quality standards. The established method was evaluated for sensitivity, specificity and reproducibility, and the authenticity of the commercially available samples was identified. Results demonstrated that based on the ITS2 sequences, F. ussuriensis and its mixed forgeries could be distinguished. The PCR products of the authentic F. ussuriensis on test strips showed two bands in the T and C lines, while the pseudo products and negative control showed only one band in the C line, which was consistent with the results of agarose gel electrophoresis. The specificity was 100%, and the sensitivity of the PCR-nucleic acid test strip was up to 0.1 ng·μL^-1, which was 10 times higher than that of the gel electrophoresis assay. 11 out of 16 commercially available samples of F. ussuriensis were qualified, and 5 were unqualified. Collectively, the PCR-nucleic acid test strip method established in this study is specific, rapid, accurate and visualized, which can provide a new technical idea for the detection of F. ussuriensis.

Objective:To study influence of Connect-Introduce-Communicate-Ask-Respond-Exit(CICARE)communication mode on patients with acute heart failure(AHF).Methods:A total of 156 AHF patients treated in our hospital were randomly and equally divided into routine nursing group and CICARE group(received CICARE communication mode based on routine nursing group).Both groups were intervened for one month.General clinical data,hospitalization indexes,scores of Hamilton rating scale for depression(HAMD),Hamilton rating scale for anxiety(HAMA),general self-efficacy scale(GSES)and quality of life scale(QOL-35)before and after inter-vention and incidence of complications were compared between two groups.Results:Compared with routine nursing group,there were significant reductions in first aid time[(42.06±9.77)s vs.(20.27±3.77)s],visit time[(95.67±23.18)min vs.(50.07±11.21)min],admission time[(3.22±0.36)min vs.(2.60±0.67)min]and hospital stay[(22.33±4.82)d vs.(14.13±2.42)d];and scores of HAMD[(14.02±1.42)scores vs.(6.04± 1.57)scores]and HAMA[(13.24±2.07)scores vs.(7.16±2.17)scores]after intervention,and significant rise in scores of GSES[(14.25±3.14)scores vs.(32.03±6.06)scores]and QOL-35[(70.67±5.75)scores vs.(86.93±5.51)scores]in CICARE group after intervention(P=0.001 all).Incidence rate of complications in CICARE group was significantly lower than that of CICARE group(5.13％vs.20.51％,P=0.004).Conclusion:CICARE communication mode can significantly alleviate adverse emotions and improve self-efficacy in patients with acute heart failure.

Objective To explore the antitumor effects of metformin on ovarian cancer cells in vitro, particularly on tumor cell proliferation, cell cycle, apoptosis, migration, and possible mechanism. Methods Ovarian cancer cell lines (A2780, CAOV3, and SKOV3) were treated with different concentrations of metformin. Their proliferation was explored using the MTT and clone formation assays, cell migration was examined using the scratch and Transwell assays, and cell cycle and apoptosis were examined using flow cytometry. In addition, metformin’s effects on the phosphorylation of AMPK and mTOR and the expression of CXCR4 and Wnt/β-catenin protein was measured by Western blot. Results The survival rates of ovarian cancer cells decreased significantly with increasing metformin concentration and metformin treatment time. The IC₅₀ values of metformin at 48 h for A2780, CAOV3, and SKOV3 cells were 16.36, 36.65, and 43.44 mmol/L, respectively. Compared with the control group, the clone formation ability and cell migration ability of ovarian cancer cells were significantly inhibited by metformin treatment and cell cycle arrested at the G₀/G₁ phase, and the apoptosis rate increased. As metformin concentration increased, the expression of phosphorylated AMPK protein gradually increased, and the expression levels of phosphorylated mTOR, CXCR4, Dvl3, β-catenin, cyclin D1, and CDK1 decreased. Conclusion Metformin exerts an antitumor effect on ovarian cancer cells, which is related to the activation of AMPK to inhibit CXCR4-mediated Wnt/β-catenin signaling pathway.

Humans ; Vascular Stiffness ; Coal Mining ; Occupational Diseases/epidemiology* ; Risk Factors ; Coal ; Miners

After entering the body from the drug delivery site, antitumor nanomedicines need to cross a series of physiopathological barriers to reach the target site of action to effectively exert antitumor therapeutic effects. The ligand modification strategy is a classic method to enhance the efficiency of nanomedicine delivery in vivo, but the contradiction between the single ligand modification strategy, which is characterized by unity and stage, and the in vivo delivery process, which is characterized by versatility and whole-process characteristics, determines that nanomedicines modified by a single ligand alone cannot satisfy the target efficacy requirements. Therefore, the use of multiligand combinatorial modification strategies by virtue of nanomedicine surface area advantages is key to advancing the next generation of smart nanomedicines. In this paper, on the basis of summarizing and classifying the commonly used functional ligands for in vivo delivery, the advantages and research progress of multiligand combination modification of antitumor nanomedicines are discussed with special focus, and the multiligand combination modification is classified as synergistic and complementary according to the combination of the ligands, which is of great significance to ensure that antitumor nanomedicines can overcome the multiple physiopathological barriers to achieve precise delivery.