Objective To investigate the prevalence of Clonorchis sinensis human infections in Congjiang County, Guizhou Province in 2023, so as to provide insights into formulation of the clonorchiasis control strategy. Methods Congjiang County was divided into eastern, western, southern, northern and central areas according to the geographical locations, and one township was randomly sampled from each area. Then, each administrative village was randomly sampled from each township, and 200 permanent residents over 3 years of age were randomly sampled from each village. Participants’ stool samples were collected for detection of C. sinensis eggs with the Kato-Katz technique (two slides for each stool sample), and the prevalence and intensity of C. sinensis infections were calculated. In addition, the risk factors of clonorchiasis were identified among participants using a questionnaire survey. Results A total of 1 001 residents were included, and the prevalence of C. sinensis infections was 16.28% (163/1 001), with mild infections as the predominant category of infection intensity [73.01% (119/163)]. The prevalence rates of C. sinensis human infections were 30.50% (61/200), 1.50% (3/200), 30.35% (61/201), 12.50% (25/200), and 6.50% (13/200) at five survey sites, respectively (χ² = 107.03, P < 0.05), and there was a significant difference in the prevalence of C. sinensis infections between men [22.44% (112/499)] and women [10.16% (51/502)] (χ² = 27.71, P < 0.05). The prevalence of C. sinensis infections was relatively high among participants at ages of 60 to 70 years [26.14% (23/88)], public servants [46.15% (6/13)], and Han ethnic participants [33.33% (5/15)]. The prevalence of C. sinensis infections was higher among participants with a habit of consuming raw or un-dercooked freshwater fish and shrimp [22.06% (90/408)] than among those without the habit [12.31% (73/593)] (χ² = 16.85, P < 0.05), and there was no significant difference in the prevalence of C. sinensis infections between participants with [13.99% (41/293)] and without separation of raw and cooked chopping boards [17.23% (122/708)] (χ² = 1.59, P > 0.05). In addition, the prevalence of C. sinensis infections was 8.70% (2/23) and 16.46% (161/978) among participants with and without fever complicated by discomfort in the right upper abdomen during the past half year (χ² = 0.99, P > 0.05). Conclusions The prevalence of C. sinensis human infections was high in Congjiang County, Guizhou Province in 2023, and infections predominantly occurred among young and middle-aged men. Intensified health education among high-risk residents and alteration of dietary habits of consuming raw or undercooked freshwater fish or shrimp are recommended to reduce the prevalence of C. sinensis human infections.

ObjectiveGastric hemorrhage is one of the most common and life-threatening emergencies of the upper digestive tract. Early identification and continuous monitoring are essential for reducing rebleeding rates and mortality, particularly within the critical early hours after onset. Although endoscopy and radiological imaging can accurately localize bleeding sites, these approaches are invasive, resource-intensive, and unsuitable for continuous bedside monitoring. Electrical impedance tomography (EIT), as a noninvasive and radiation-free functional imaging technique, offers real-time visualization of conductivity distribution and has the potential for detecting intragastric bleeding based on the electrical contrast between blood and surrounding gastric tissues. In this study, a three-dimensional gastric EIT (3D-gEIT) framework is proposed to achieve noninvasive, real-time, and dynamic monitoring of gastric hemorrhage, with emphasis on spatial localization and quantitative volume assessment. MethodsA three-dimensional upper-abdominal simulation model incorporating the stomach, gastric wall, gastric contents, and surrounding tissues was established. Three electrode configurations, namely the dual layer ring, the four layer staggered ring, and the opposed dual plane array, were designed and systematically compared to evaluate their influence on depth sensitivity and spatial resolution. Based on the Tikhonov-Noser hybrid regularization scheme, a region-clustering constraint was introduced to develop the TK-Noser-RCC algorithm. This approach aggregates spatially adjacent elements with similar conductivity variations, thereby enhancing structural continuity and suppressing isolated noise artifacts. To validate the proposed framework, an upper-abdominal physical phantom was constructed using agar to simulate background tissue conductivity. Hemispherical high-conductivity inclusions with volumes ranging from 10 ml to 50 ml were attached to the inner gastric wall to mimic localized bleeding under different gastric filling states. Boundary voltages were acquired under a 120 kHz excitation current and reconstructed using the TK-Noser-RCC algorithm. Furthermore, an in vivo animal experiment was performed using a porcine model with adult-scale abdominal dimensions. A total of 100 ml of autologous blood was injected incrementally into the stomach to simulate progressive gastric hemorrhage, and time-difference EIT reconstruction was conducted at each injection stage to assess the dynamic system response under physiological conditions. ResultsSimulation results demonstrated that the opposed dual-plane electrode array achieved superior depth sensitivity distribution and spatial resolution. For a 40 ml hemorrhage model, the average ICC and SSIM improved by 55.9% and 38.8% compared with the dual-layer ring configuration, and by 64.0% and 39.5% compared with the four-layer staggered configuration. The proposed region-clustering constraint significantly enhanced reconstruction stability. Under added Gaussian noise of 40 dB and 30 dB, ICC values remained approximately 0.85, indicating effective artifact suppression and preservation of boundary integrity. In physical phantom experiments, reconstructed hemorrhage volumes increased approximately linearly with the preset hemispherical volumes, and the reconstructed high-conductivity regions closely matched the actual bleeding locations. Both empty-stomach and full-stomach conditions were evaluated, demonstrating that the opposed dual-plane configuration maintained stable imaging performance across varying gastric contents. In the animal experiment, reconstructed low-impedance regions expanded progressively with increasing injected blood volume. The spatial localization of the hemorrhage remained stable throughout the procedure, and no significant artifacts were observed. Quantitative analysis showed that reconstructed volume and average conductivity variation exhibited an approximately linear growth trend with injected blood volume, confirming the sensitivity of the system to dynamic intragastric conductivity changes. ConclusionThe proposed 3D-gEIT framework enables quantitative reconstruction of gastric hemorrhage volume and spatial distribution with improved depth sensitivity, structural continuity, and noise robustness compared with conventional EIT approaches. By integrating optimized electrode configuration and a region-clustering-constrained reconstruction algorithm, the system provides stable dynamic monitoring under both controlled phantom conditions and in vivo physiological environments. This method offers a noninvasive, real-time, and low-cost imaging strategy for early diagnosis, postoperative monitoring, and bedside surveillance of gastric bleeding.

ObjectiveTo investigate the effects and underlying mechanisms of Shenqi Wenfei prescription （SQWF） on chronic obstructive pulmonary disease （COPD）. MethodsA rat model of COPD with lung Qi deficiency was established using lipopolysaccharide （LPS） combined with cigarette smoke. Forty-eight SD rats were randomly divided into a blank group， a model group， low-， medium-， and high-dose SQWF groups （2.835， 5.67， 11.34 g·kg^-1）， and a Yupingfeng group （1.35 g·kg^-1）. Drug administration began on day 29 after modeling and continued for 2 weeks. The general condition of the rats was observed， and the lung function in each group was assessed. Hematoxylin-eosin （HE） staining was used to observe pathological changes in lung tissue. The proportion of inflammatory cells in bronchoalveolar lavage fluid （BALF） was measured. Apoptosis in lung tissue was examined by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling （TUNEL） staining. The release level of lactate dehydrogenase （LDH） in BALF was detected by a microplate assay. Reactive oxygen species （ROS） levels in lung tissue were detected using fluorescent probes. The levels of malondialdehyde （MDA）， total superoxide dismutase （SOD）， and reduced glutathione （GSH） in BALF were measured by biochemical methods. Ultrastructural changes in lung cells were observed via transmission electron microscopy. Double immunofluorescence staining was performed to detect the expression of thioredoxin-interacting protein （TXNIP） and nucleotide-binding oligomerization domain-like receptor protein 3 （NLRP3） in lung tissue. Western blot analysis was used to detect the protein expression of TXNIP， NLRP3， apoptosis-associated speck-like protein containing a CARD （ASC）， cysteinyl aspartate-specific protease-1 （Caspase-1）， Caspase-1 p20， gasdermin D （GSDMD）， GSDMD N-terminal active fragment （GSDMD-N）， interleukin-1β （IL-1β）， and IL-18 in lung tissue. Serum IL-1β and IL-18 levels were measured by ELISA. ResultsCompared with the blank group， the model group showed lassitude， fatigue， tachypnea， and audible phlegm sounds， and lung function significantly declined （P0.01）. Pulmonary emphysema and inflammatory cell infiltration were obvious. The level of inflammatory cells in BALF increased significantly （P0.05）. The number of TUNEL-positive cells increased （P0.01）. Levels of LDH， ROS， and MDA in BALF increased significantly （P0.01）， while GSH and SOD activities decreased significantly （P0.01）. Lung tissue cells showed irregular morphology， swollen mitochondria， disrupted cell membranes， and abundant vesicles， i.e.， pyroptotic bodies. Protein levels of TXNIP， NLRP3， ASC， Caspase-1， Caspase-1 p20， GSDMD， GSDMD-N， IL-1β， and IL-18 in lung tissue were significantly elevated （P0.01）， and serum IL-1β and IL-18 levels also increased significantly （P0.01）. Compared with the model group， each medication group showed alleviation of qi deficiency symptoms and improved lung function （P0.01）. Pulmonary emphysema and inflammatory cell infiltration were reduced. Inflammatory cell levels decreased （P0.05）. The number of TUNEL-positive cells decreased significantly （P0.01）. Levels of LDH， ROS， and MDA decreased significantly （P0.05）， while GSH and SOD activities significantly increased （P0.01）. Morphological and structural damage in lung tissue was improved to varying degrees. Protein levels of TXNIP， NLRP3， ASC， Caspase-1， Caspase-1 p20， GSDMD， GSDMD-N， IL-1β， and IL-18 in lung tissue significantly decreased （P0.01）， and serum IL-1β and IL-18 levels also decreased significantly （P0.05）. ConclusionSQWF can improve lung function and alleviate inflammatory responses in COPD rats. Its mechanism may be related to regulating the ROS/TXNIP/NLRP3 pathway and inhibiting pyroptosis.

ObjectiveTo investigate the effects and underlying mechanisms of Shenqi Wenfei prescription （SQWF） on chronic obstructive pulmonary disease （COPD）. MethodsA rat model of COPD with lung Qi deficiency was established using lipopolysaccharide （LPS） combined with cigarette smoke. Forty-eight SD rats were randomly divided into a blank group， a model group， low-， medium-， and high-dose SQWF groups （2.835， 5.67， 11.34 g·kg^-1）， and a Yupingfeng group （1.35 g·kg^-1）. Drug administration began on day 29 after modeling and continued for 2 weeks. The general condition of the rats was observed， and the lung function in each group was assessed. Hematoxylin-eosin （HE） staining was used to observe pathological changes in lung tissue. The proportion of inflammatory cells in bronchoalveolar lavage fluid （BALF） was measured. Apoptosis in lung tissue was examined by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling （TUNEL） staining. The release level of lactate dehydrogenase （LDH） in BALF was detected by a microplate assay. Reactive oxygen species （ROS） levels in lung tissue were detected using fluorescent probes. The levels of malondialdehyde （MDA）， total superoxide dismutase （SOD）， and reduced glutathione （GSH） in BALF were measured by biochemical methods. Ultrastructural changes in lung cells were observed via transmission electron microscopy. Double immunofluorescence staining was performed to detect the expression of thioredoxin-interacting protein （TXNIP） and nucleotide-binding oligomerization domain-like receptor protein 3 （NLRP3） in lung tissue. Western blot analysis was used to detect the protein expression of TXNIP， NLRP3， apoptosis-associated speck-like protein containing a CARD （ASC）， cysteinyl aspartate-specific protease-1 （Caspase-1）， Caspase-1 p20， gasdermin D （GSDMD）， GSDMD N-terminal active fragment （GSDMD-N）， interleukin-1β （IL-1β）， and IL-18 in lung tissue. Serum IL-1β and IL-18 levels were measured by ELISA. ResultsCompared with the blank group， the model group showed lassitude， fatigue， tachypnea， and audible phlegm sounds， and lung function significantly declined （P0.01）. Pulmonary emphysema and inflammatory cell infiltration were obvious. The level of inflammatory cells in BALF increased significantly （P0.05）. The number of TUNEL-positive cells increased （P0.01）. Levels of LDH， ROS， and MDA in BALF increased significantly （P0.01）， while GSH and SOD activities decreased significantly （P0.01）. Lung tissue cells showed irregular morphology， swollen mitochondria， disrupted cell membranes， and abundant vesicles， i.e.， pyroptotic bodies. Protein levels of TXNIP， NLRP3， ASC， Caspase-1， Caspase-1 p20， GSDMD， GSDMD-N， IL-1β， and IL-18 in lung tissue were significantly elevated （P0.01）， and serum IL-1β and IL-18 levels also increased significantly （P0.01）. Compared with the model group， each medication group showed alleviation of qi deficiency symptoms and improved lung function （P0.01）. Pulmonary emphysema and inflammatory cell infiltration were reduced. Inflammatory cell levels decreased （P0.05）. The number of TUNEL-positive cells decreased significantly （P0.01）. Levels of LDH， ROS， and MDA decreased significantly （P0.05）， while GSH and SOD activities significantly increased （P0.01）. Morphological and structural damage in lung tissue was improved to varying degrees. Protein levels of TXNIP， NLRP3， ASC， Caspase-1， Caspase-1 p20， GSDMD， GSDMD-N， IL-1β， and IL-18 in lung tissue significantly decreased （P0.01）， and serum IL-1β and IL-18 levels also decreased significantly （P0.05）. ConclusionSQWF can improve lung function and alleviate inflammatory responses in COPD rats. Its mechanism may be related to regulating the ROS/TXNIP/NLRP3 pathway and inhibiting pyroptosis.

The welfare and ethics of laboratory animals are the ethical principles and behavioral norms that need to be followed in conducting animal-based scientific research, breeding and managing laboratory animals, and supervising and regulating such activities. The level of protection of laboratory animal welfare and ethics is closely related to the development of science and technology, which has become a widely recognized international consensus. At present, Guangdong Province is accelerating the construction of a high-level science and technology innovation province and the Guangdong-Hong Kong-Macao Greater Bay Area International Science and Technology Innovation Center. Guangdong Province should rely on its advanced governance capacity in the field of laboratory animal science and technology ethics to promote the high-quality development of its laboratory animal science and technology sector. Based on the management laws, regulations, and institutional mechanisms of laboratory animals in China, this paper explores the optimization of the laboratory animal science and technology ethics governance system, which includes the institutional guarantees, responsibility systems, ethical review and supervision mechanisms, and education and outreach. Through methods such as literature research, questionnaire surveys, and interview investigations, an empirical study of the laboratory animal science and technology ethics governance system in Guangdong Province has been conducted. Analysis of literature and research results shows that Guangdong Province has basically established a laboratory animal management system, collaboration mechanism, supervision mechanism, and education and training system that meet the current requirements of the laboratory animal science and technology ethics governance system in China. However, there are still problems such as an incomplete laboratory animal science and technology ethics supervision mechanism, an underdeveloped operation mechanism of review institutions, insufficient attention paid by laboratory animal units to the ethical review of animal experiments, inconsistent ethical review standards, and a lack of professional ethical education and training for ethics review personnel. Therefore, optimization measures such as improving the laboratory animal science and technology ethics review system, strengthening supervision and inspection, further strengthening the accountability of responsible entities, formulating review norms, and enhancing hierarchical and classified education and training are proposed, to provide a theoretical basis for promoting the normalized and long-term governance of laboratory animal science and technology ethics in Guangdong Province.

: To analyze the prevalence of anemia and iron deficiency among primary and secondary school students in Rural Nutrition Improvement Program areas of Guizhou Province in 2023, and to explore the related factors, so as to provide evidence for Rural Nutrition Improvement Program optimization. Methods: In September 2023, a stratified random cluster sampling strategy was used to select 40 rural compulsory education schools with rural nutrition improvement program in five counties of Guizhou Province. School level questionnaire was employed to collect information of basic characteristics and school meal implementation. A total of 7 826 primary and secondary school students aged 6-16 underwent anthropometry and hemoglobin (Hb) determination; serum ferritin (SF) was additionally measured in a random subsample of 1 795 pupils. Students in Grade 3 and above also completed a questionnaire covering demographic characteristics, dietary behaviours and nutrition knowledge. Group comparisons were conducted by Chi square test or Fisher s exact test, and multivariable Logistic regression models were constructed to identify factors associated with anemia and iron deficiency. Results: The overall Hb level was (133.21±12.95)g/L, with an anemia prevalence of 7.17%. The overall SF level was (69.58±59.01)μg/L, with an iron deficiency prevalence of 2.73%. Multivariable analysis showed that stunting ( OR =1.88), school menus without nutrient calculation ( OR =1.61) and absence of menu planning software in the current semester ( OR =2.34) independently increased anemia risk, whereas obesity reduced it ( OR =0.54) (all P <0.05). Girls ( OR =4.16) and Grades 7-9 ( OR =5.93) increased iron deficiency risk (both P <0.05). Compared with rarely eating fresh vegetables, students with consuming <3 kinds per day ( OR =0.08) or exactly 3 kinds per day ( OR =0.06) had lower iron deficiency risks (both P <0.05). Conclusions Anemia and iron deficiency are prevalent among primary and secondary school students in Guizhou. Targeted intervention measures should be implemented for key populations to enhance the effectiveness of nutrition improvement program.

ObjectiveTo evaluate the clinical efficacy of Maxing Loushi decoction in the treatment of acute exacerbation of chronic obstructive pulmonary disease （AECOPD） with phlegm turbidity obstructing lung syndrome， and to investigate its effects on inflammatory factors， immune function， and the programmed death-1（PD-1）/programmed death-ligand 1 （PD-L1） signaling pathway. MethodsA randomized controlled study was conducted， enrolling 90 hospitalized patients with AECOPD and phlegm turbidity obstructing lung syndrome in the Respiratory and Emergency Departments of Dongzhimen Hospital， Beijing University of Chinese Medicine， from April 2024 to December 2024. Patients were randomly assigned to a control group and an observation group using a random number table， with 45 patients in each group. The control group received conventional Western medical treatment， while the observation group received additional Maxing Loushi decoction for 14 days. Clinical efficacy， COPD Assessment Test （CAT） score， modified Medical Research Council Dyspnea Scale （mMRC）， 6-minute walk test （6MWT）， serum inflammatory factors， T lymphocyte subsets， and serum PD-1/PD-L1 levels were compared between the two groups before and after treatment. ResultsThe total clinical effective rate was 78.57% （33/42） in the control group and 95.35% （41/43） in the observation group， with the observation group showing significantly higher efficacy than that of the control group. The difference was statistically significant （χ² = 5.136， P<0.05）. After treatment， both groups showed significant reductions in CAT and mMRC scores （P<0.05， P<0.01） and significant increases in 6MWT compared to baseline （P<0.01）. The observation group demonstrated significantly greater improvements than the control group in this regard. Levels of inflammatory markers including C-reactive protein （CRP）， procalcitonin （PCT）， interleukin-6 （IL-6）， tumor necrosis factor-α （TNF-α）， monocyte chemoattractant protein-1（MCP-1）， and macrophage inflammatory protein-1α （MIP-1α） were significantly reduced in both groups （P<0.05， P<0.01）， with greater reductions in the observation group （P<0.05， P<0.01）. CD8⁺ levels were significantly reduced （P<0.01）， while CD3⁺， CD4⁺， and CD4⁺/CD8⁺ levels were significantly increased in both groups after treatment （P<0.05， P<0.01）， with more significant improvements observed in the observation group （P<0.05， P<0.01）. Serum PD-1 levels were reduced （P<0.05， P<0.01）， and PD-L1 levels were increased significantly in both groups after treatment （P<0.05， P<0.01）， with more pronounced changes in the observation group （P<0.05）. ConclusionMaxing Loushi decoction demonstrates definite therapeutic efficacy as an adjunctive treatment for patients with AECOPD and phlegm turbidity obstructing lung syndrome. It contributes to reducing serum inflammatory factors， improving immune function， and regulating the PD-1/PD-L1 signaling pathway.

ObjectiveTo evaluate the clinical efficacy of Maxing Loushi decoction in the treatment of acute exacerbation of chronic obstructive pulmonary disease （AECOPD） with phlegm turbidity obstructing lung syndrome， and to investigate its effects on inflammatory factors， immune function， and the programmed death-1（PD-1）/programmed death-ligand 1 （PD-L1） signaling pathway. MethodsA randomized controlled study was conducted， enrolling 90 hospitalized patients with AECOPD and phlegm turbidity obstructing lung syndrome in the Respiratory and Emergency Departments of Dongzhimen Hospital， Beijing University of Chinese Medicine， from April 2024 to December 2024. Patients were randomly assigned to a control group and an observation group using a random number table， with 45 patients in each group. The control group received conventional Western medical treatment， while the observation group received additional Maxing Loushi decoction for 14 days. Clinical efficacy， COPD Assessment Test （CAT） score， modified Medical Research Council Dyspnea Scale （mMRC）， 6-minute walk test （6MWT）， serum inflammatory factors， T lymphocyte subsets， and serum PD-1/PD-L1 levels were compared between the two groups before and after treatment. ResultsThe total clinical effective rate was 78.57% （33/42） in the control group and 95.35% （41/43） in the observation group， with the observation group showing significantly higher efficacy than that of the control group. The difference was statistically significant （χ² = 5.136， P<0.05）. After treatment， both groups showed significant reductions in CAT and mMRC scores （P<0.05， P<0.01） and significant increases in 6MWT compared to baseline （P<0.01）. The observation group demonstrated significantly greater improvements than the control group in this regard. Levels of inflammatory markers including C-reactive protein （CRP）， procalcitonin （PCT）， interleukin-6 （IL-6）， tumor necrosis factor-α （TNF-α）， monocyte chemoattractant protein-1（MCP-1）， and macrophage inflammatory protein-1α （MIP-1α） were significantly reduced in both groups （P<0.05， P<0.01）， with greater reductions in the observation group （P<0.05， P<0.01）. CD8⁺ levels were significantly reduced （P<0.01）， while CD3⁺， CD4⁺， and CD4⁺/CD8⁺ levels were significantly increased in both groups after treatment （P<0.05， P<0.01）， with more significant improvements observed in the observation group （P<0.05， P<0.01）. Serum PD-1 levels were reduced （P<0.05， P<0.01）， and PD-L1 levels were increased significantly in both groups after treatment （P<0.05， P<0.01）， with more pronounced changes in the observation group （P<0.05）. ConclusionMaxing Loushi decoction demonstrates definite therapeutic efficacy as an adjunctive treatment for patients with AECOPD and phlegm turbidity obstructing lung syndrome. It contributes to reducing serum inflammatory factors， improving immune function， and regulating the PD-1/PD-L1 signaling pathway.

Objective To investigate the efficacy and safety of the Corheart 6 left ventricular assist system in patients with end-stage heart failure. Methods A retrospective study was conducted on patients with end-stage heart failure who were treated with Corheart 6 left ventricular assist system from March 2022 to June 2024 in 4 hospitals in Jiangsu Province. The efficacy of the device was evaluated by comparing changes in clinical indicators at preoperative, discharge, 3-month postoperative, and 6-month postoperative timepoints, including the New York Heart Association (NYHA) functional classification, left ventricular ejection fraction (LVEF), and left ventricular end-diastolic diameter (LVEDD). The safety of the device was assessed by analyzing the intraoperative position and orientation of the blood pump inlet cannula, as well as the incidence of adverse events. Results In this study, 39 patients were collected, including 34 males and 5 females with a mean age of (56.4±12.5) years, ranging from 20 to 75 years. There was no operative death. There was no death in postoperative 3 months with a survival rate of 100.0%. There were 3 deaths in 6 months postoperatively, with a survival rate of 92.3%. All patients had a preoperative NYHA cardiac function classification of class Ⅳ. The NYHA cardiac function class of the patients improved (P<0.05) at discharge, 3 and 6 months after surgery when compared to the preoperative period. LVEF was significantly higher at 3 months after surgery than that during the preoperative period (P<0.05). LVEDD was significantly smaller at discharge, 3 and 6 months after surgery than that during the preoperative period (P<0.05). The safety evaluation's findings demonstrated that all 39 patients' intraoperative blood pump inlet tubes were oriented correctly, the artificial blood vessel suture sites were appropriate, there were no instances of device malfunction or pump thrombosis, or instances of bleeding or hemolysis, and the rate of the remaining adverse events was low. Conclusion With a low rate of adverse events and an excellent safety profile, the Corheart 6 left ventricular assist system can efficiently enhance cardiac function in patients with end-stage heart failure. It also has considerable clinical uses.

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.