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.

Amid the global wave of digital economy, China's medical artificial intelligence applications are rapidly advancing through technological innovation and policy support, while facing multifaceted evaluation and regulatory challenges. The dynamic algorithm evolution undermines the consistency of assessment criteria, multimodal systems lack unified evaluation metrics, and conflicts persist between data sharing and privacy protection. To address these issues, the China National Health Development Research Center has established a value assessment framework for artificial intelligence medical technologies, formulated the country's first technical guideline for clinical evaluation, and validated their practicality through scenario-based pilot studies. Furthermore, this paper proposes introducing a "regulatory sandbox" model to test technical compliance in controlled environments, thereby balancing innovation incentives with risk governance.
Artificial Intelligence/legislation & jurisprudence* ; China ; Humans ; Algorithms

OBJECTIVE: To investigate the effect of miR-483-5p on hepatocellular carcinoma (HCC) cells proliferation and stemness, as well as the attenuating effect of Pien Tze Huang (PZH). METHODS: Differentially expressed miRNA between HepG2 cells and hepatic cancer stem-like cells (HCSCs) were identified by a miRNA microarray assay. miR-483-5p mimics were transfected into HepG2 cells to explore the effects of miR-483-5p on cell proliferation and stemness. HepG2 cells and HCSCs were treated with PZH (0, 0.25, 0.50 and 0.75 mg/mL) to explore the effects of PZH on the proliferation and stemness, both in non-induced state and the state induced by miR-483-5p mimics. RESULTS: miR-483-5p was significantly up-regulated in HCSCs and its overexpression increased cell proliferation and stemness in HepG2 cells (P<0.05). PZH not only significantly inhibited proliferation in HepG2 cells, but also significantly suppressed the cell proliferation and self-renewal of HCSCs (P<0.05). The effects of miR-483-5p mimics on proliferation and stemness of HepG2 cells were partially abolished by PZH. CONCLUSIONS miR-483-5p promotes proliferation and enhances stemness of HepG2 cells, which were attenuated by PZH, demonstrating that miR-483-5p is a potential molecular target for the treatment of HCC and provide experimental evidence to support clinical use of PZH for patients with HCC.
Humans ; MicroRNAs/metabolism* ; Cell Proliferation/drug effects* ; Liver Neoplasms/drug therapy* ; Carcinoma, Hepatocellular/drug therapy* ; Hep G2 Cells ; Neoplastic Stem Cells/metabolism* ; Drugs, Chinese Herbal/therapeutic use* ; Gene Expression Regulation, Neoplastic/drug effects*

Genitourinary tract infections caused by Chlamydia trachomatis ( Ct) are characterized by their insidious onset, mild symptoms, and prolonged disease course, making them challenging to treat effectively. Chronic persistent infections and associated complications impose a significant burden on both patients and society. Numerous studies have shown that relying solely on antibiotics as first-line therapy may not be sufficient to completely eradicate urogenital Ct infections. Additionally, antibiotic use can lead to the development of Ct resistance and disrupt the body′s microbial balance. Therefore, the development of novel Ct inhibitors is crucial. This review summarizes recent advances in research on Ct inhibitors, aiming to provide a valuable reference for both basic research and clinical treatment of urogenital Ct infections.

Objective:This paper measures and analyzes the supply levels across districts,and explore the equity status and spatial-temporal evolution characteristics of medical resource supply during the 13th Five-Year Plan to the14th Five-Year Plan periods,aiming to provide references for future planning.Methods:Based on the public service population radiation model,the radiation population numbers of each district in Beijing in each year are calculated.Literature-based relevant indicators are selected.The improved CRITIC-entropy weight method is used to measure the supply level of each medical and health institutions.District-level supply levels per 100,000 radiated population were calculated using population density weighting.And the Gini coefficient and Moran's index are used to analyze its spatial and temporal distribution equilibrium.Results:During the 13th Five-Year Plan to the 14th Five-Year Plan periods,the overall medical resource supply level in Beijing showed an upward trend,with a slight decline in core areas and significant growth in urban development new towns.Regional disparities narrowed,and the global Moran's index values indicated positive spatial correlations in supply levels.Conclusion:The decentralization of non-capital functions in Beijing has achieved notable results,though improvements in outer suburbs remain gradual.Future efforts should strengthen cross-regional coordination,integrate innovations like internet-based medical consultations,and promote a more balanced healthcare resource supply structure aligned with public health needs.

Objective:To analyze the development trend of medical institution bed allocation in OECD countries and provide insights for optimizing bed resources allocation in China.Methods:Data on indicators of bed allocation and related factors from 1991 to 2022 were collected from the OECD online database.Bed allocation impact dimensions were identified based on health needs and demand theories.The random effect model and correlation analysis were used to explore influencing pathways of bed allocation.Results:The number of beds per 1 000 population and average life expectancy showed a significant positive correlation in countries below the average bed level,while an inverse trend was observed in countries above the average level.The number of long-term care beds per 1000 population showed positive correlation with average life expectancy.Multidimensional factors such as the disease spectrum and bed utilization efficiency were significant correlated with the bed allocation levels.The greater the gap in inpatient and outpatient reimbursement rations,the higher the demand for hospitalization among patients with chronic disease.Conclusions:An optimal number of beds is essential for achieving higher health outcomes.The bed classification planning system should be designed to adapt to demographic changes and strengthen the medical security support system.

Objective To establish a stable,reliable,and clinically relevant porcine model of endotoxin-induced acute respiratory distress syndrome(ARDS).Methods Ten 8-month-old male Bama minipigs were deeply sedated,followed by invasive mechanical ventilation and electrocardiographic monitoring.Lipopolysaccharide(LPS)was intravenously pumped at 600 μg/(kg·h)for 3 hours,then maintained at 15 μg/(kg·h)thereafter.Dynamic monitoring was performed at five time points after LPS injection(LPS 0,1,3,5,and 8 h),including arterial blood gas analysis and chest computed tomography(CT)scans.Pathological examination of lung tissues obtained via bronchoscopic biopsy(HE staining and transmission electron microscopy)was conducted.These indicators were comprehensively used to evaluate the success of the animal model.Results At 5 hours after LPS administration,8 minipigs developed symptoms such as skin cyanosis,elevated body temperature,and respiratory distress.The oxygenation index decreased to<300 mmHg.Chest CT scans showed diffuse pulmonary infiltrates.Histopathology revealed alveolar edema and hyaline membrane formation.Transmission electron microscopy demonstrated disruption of pulmonary blood-air barrier,depletion of lamellar bodies in type Ⅱ pneumocytes,inflammatory cell infiltration,and exudation of plasma proteins and fibrin.Compared with LPS 0 h,at LPS 8 h,the oxygenation index and arterial blood pH were significantly decreased(P<0.001),while blood lactic acid and serum potassium were significantly increased(P<0.05);serum calcium and base excess were significantly decreased(P<0.05),and the lung injury score based on HE-stained lung sections was significantly increased(P<0.01).Conclusion The porcine ARDS model established by continuous LPS injection can dynamically simulate the pathophysiological characteristics and typical pathological manifestations of clinical septic ARDS,making it an effective tool to study the pathogenesis,prevention,and treatment strategies of septic ARDS.

Objective:To analyze the development trend of medical institution bed allocation in OECD countries and provide insights for optimizing bed resources allocation in China.Methods:Data on indicators of bed allocation and related factors from 1991 to 2022 were collected from the OECD online database.Bed allocation impact dimensions were identified based on health needs and demand theories.The random effect model and correlation analysis were used to explore influencing pathways of bed allocation.Results:The number of beds per 1 000 population and average life expectancy showed a significant positive correlation in countries below the average bed level,while an inverse trend was observed in countries above the average level.The number of long-term care beds per 1000 population showed positive correlation with average life expectancy.Multidimensional factors such as the disease spectrum and bed utilization efficiency were significant correlated with the bed allocation levels.The greater the gap in inpatient and outpatient reimbursement rations,the higher the demand for hospitalization among patients with chronic disease.Conclusions:An optimal number of beds is essential for achieving higher health outcomes.The bed classification planning system should be designed to adapt to demographic changes and strengthen the medical security support system.

Objective:This paper measures and analyzes the supply levels across districts,and explore the equity status and spatial-temporal evolution characteristics of medical resource supply during the 13th Five-Year Plan to the14th Five-Year Plan periods,aiming to provide references for future planning.Methods:Based on the public service population radiation model,the radiation population numbers of each district in Beijing in each year are calculated.Literature-based relevant indicators are selected.The improved CRITIC-entropy weight method is used to measure the supply level of each medical and health institutions.District-level supply levels per 100,000 radiated population were calculated using population density weighting.And the Gini coefficient and Moran's index are used to analyze its spatial and temporal distribution equilibrium.Results:During the 13th Five-Year Plan to the 14th Five-Year Plan periods,the overall medical resource supply level in Beijing showed an upward trend,with a slight decline in core areas and significant growth in urban development new towns.Regional disparities narrowed,and the global Moran's index values indicated positive spatial correlations in supply levels.Conclusion:The decentralization of non-capital functions in Beijing has achieved notable results,though improvements in outer suburbs remain gradual.Future efforts should strengthen cross-regional coordination,integrate innovations like internet-based medical consultations,and promote a more balanced healthcare resource supply structure aligned with public health needs.