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.

Aim To study the effect of menthol on hypobaric hypoxia-induced pulmonary arterial hypertension and explore the underlying mechanism in mice. Methods 10 to 12 weeks old wild type (WT) mice and TRPM8 gene knockout (TRPM8

Objective To analyze the medication rules of Professor HUANG Feng for the treatment of low back pain using data mining methods.Methods The information of prescriptions for the effective cases of outpatients with low back pain treated by Professor HUANG Feng were collected and screened.Microsoft Excel 2019 was used to analyze the frequency of medication and the distribution of properties,flavors and meridian tropism of the drugs in the included prescription.IBM SPSS Modeler 18.0 was used for association rule analysis,and IBM Statistics 26.0 was used for cluster analysis.Results A total of 239 prescriptions and 75 Chinese medicines were included.There were 23 high-frequency Chinese medicines with the medication frequency being or over 20 times,and the top 10 Chinese medicines were Glycyrrhizae Radix et Rhizoma,vinegar-processed Corydalis Rhizoma,Cibotii Rhizoma,Atractylodis Macrocephalae Rhizoma,Zanthoxyli Radix,salt-processed Achyranthis Bidentatae Radix,Rehmanniae Radix,Dipsaci Radix,Coicis Semen,and Salviae Miltiorrhizae Radix et Rhizoma.The medicines were mainly warm in nature,and were sweet,bitter and pungent in flavor.Most of the drugs had the meridian tropism of liver,stomach and spleen meridians.Among the drug combinations obtained from association rule analysis with the top 20 highest support,vinegar-processed Corydalis Rhizoma,Cibotii Rhizoma,Atractylodis Macrocephalae Rhizoma and Zanthoxyli Radix were the core drugs.Cluster analysis yielded 6 clustering combinations.Conclusion For the treatment of low back pain,Professor HUANG Feng follows the principle of"treatment adapting to the climate,individuality,and environment"and"treating the root cause of the disease",usually adopts the drugs for activating blood,moving qi and relieving pain,nourishing the liver and kidney,and also uses the medicines for replenishing qi and strengthening the spleen.The ideas of HUANG Feng for the treatment of low back pain can be used as a reference for the clinical treatment.

Objective To study the pharmacokinetic characteristics of lamotrigine tablets in Chinese healthy subjects under fasting and fed conditions,and to evaluate the bioequivalence and safety profiles between the domestic test preparation and the original reference preparation.Methods Twenty-four Chinese healthy male and female subjects were enrolled under fasting and fed conditions,18 male and 6 female subjects under fasting conditions,17 male and 7 female subjects under fed conditions.A random,open,single-dose,two preparations,two sequences and double-crossover design was used.Plasma samples were collected over a 72-hour period after give the test or reference preparations 50 mg under fasting and fed conditions.The concentration of lamotrigine in plasma was detected by liquid chromatography-tandem mass spectrometry,and the main pharmacokinetic parameters were calculated to evaluate the bioequivalence by WinNonLin 8.1 program.Results The main pharmacokinetic parameters of single-dose the tested and reference preparations were as follows:The fasting condition Cmax were(910.93±248.02)and(855.87±214.36)ng·mL-1;tmax were 0.50(0.25,4.00)and 1.00(0.25,3.50)h;t1/2 were(36.1±9.2)and(36.0±8.2)h;AUC0_72h were(27 402.40±4 752.00)and(26 933.90±4 085.80)h·ng·mL-1.The fed condition Cmax were(701.62±120.67)and(718.95±94.81)ng·mL-1;tmax were 4.00(1.00,5.00)and 4.00(0.50,5.00)h;t1/2 were(44.2±12.4)and(44.0±12.0)h;AUC0-72h were(30 253.20±7 018.00)and(30 324.60±6 147.70)h·ng·mL-1.The 90％confidence intervals of the geometric mean ratios of Cmax and AUC0-72 hfor the test preparation and reference preparation were all between 80.00％and 125.00％under fasting and fed conditions.Conclusion Two kinds of lamotrigine tablets are bioequivalent,and have similar safety in Chinese healthy male and female subjects under fasting and fed conditions.

Temporomandibular joint (TMJ) diseases are common clinical conditions. The number of patients with TMJ diseases is large, and the etiology, epidemiology, disease spectrum, and treatment of the disease remain controversial and unknown. To understand and master the current situation of the occurrence, development and prevention of TMJ diseases, as well as to identify the patterns in etiology, incidence, drug sensitivity, and prognosis is crucial for alleviating patients′suffering.This will facilitate in-depth medical research, effective disease prevention measures, and the formulation of corresponding health policies. Cohort construction and research has an irreplaceable role in precise disease prevention and significant improvement in diagnosis and treatment levels. Large-scale cohort studies are needed to explore the relationship between potential risk factors and outcomes of TMJ diseases, and to observe disease prognoses through long-term follw-ups. The consensus aims to establish a standard conceptual frame work for a cohort study on patients with TMJ disease while providing ideas for cohort data standards to this condition. TMJ disease cohort data consists of both common data standards applicable to all specific disease cohorts as well as disease-specific data standards. Common data were available for each specific disease cohort. By integrating different cohort research resources, standard problems or study variables can be unified. Long-term follow-up can be performed using consistent definitions and criteria across different projects for better core data collection. It is hoped that this consensus will be facilitate the development cohort studies of TMJ diseases.

Objective This study aimed to evaluate whether the onset of the plateau phase of slow hepatitis B surface antigen decline in patients with chronic hepatitis B treated with intermittent interferon therapy is related to the frequency of dendritic cell subsets and expression of the costimulatory molecules CD40,CD80,CD83,and CD86. Method This was a cross-sectional study in which patients were divided into a natural history group(namely NH group),a long-term oral nucleoside analogs treatment group(namely NA group),and a plateau-arriving group(namely P group).The percentage of plasmacytoid dendritic cell and myeloid dendritic cell subsets in peripheral blood lymphocytes and monocytes and the mean fluorescence intensity of their surface costimulatory molecules were detected using a flow cytometer. Results In total,143 patients were enrolled(NH group,n = 49;NA group,n = 47;P group,n = 47).The results demonstrated that CD141/CD1c double negative myeloid dendritic cell(DNmDC)/lymphocytes and monocytes(%)in P group(0.041[0.024,0.069])was significantly lower than that in NH group(0.270[0.135,0.407])and NA group(0.273[0.150,0.443]),and CD86 mean fluorescence intensity of DNmDCs in P group(1832.0[1484.0,2793.0])was significantly lower than that in NH group(4316.0[2958.0,5169.0])and NA group(3299.0[2534.0,4371.0]),Adjusted P all<0.001. Conclusion Reduced DNmDCs and impaired maturation may be associated with the onset of the plateau phase during intermittent interferon therapy in patients with chronic hepatitis B.

Objective To explore characteristics of clinical parameters and cytokines in patients with drug-induced liver injury(DILI)caused by different drugs and their correlation with clinical indicators. Method The study was conducted on patients who were up to Review of Uncertainties in Confidence Assessment for Medical Tests(RUCAM)scoring criteria and clinically diagnosed with DILI.Based on Chinese herbal medicine,cardiovascular drugs,non-steroidal anti-inflammatory drugs(NSAIDs),anti-infective drugs,and other drugs,patients were divided into five groups.Cytokines were measured by Luminex technology.Baseline characteristics of clinical biochemical indicators and cytokines in DILI patients and their correlation were analyzed. Results 73 patients were enrolled.Age among five groups was statistically different(P=0.032).Alanine aminotransferase(ALT)(P=0.033)and aspartate aminotransferase(AST)(P=0.007)in NSAIDs group were higher than those in chinese herbal medicine group.Interleukin-6(IL-6)and tumor necrosis factor alpha(TNF-α)in patients with Chinese herbal medicine(IL-6:P<0.001;TNF-α:P<0.001)and cardiovascular medicine(IL-6:P=0.020;TNF-α:P=0.001)were lower than those in NSAIDs group.There was a positive correlation between ALT(r=0.697,P=0.025),AST(r=0.721,P=0.019),and IL-6 in NSAIDs group. Conclusion Older age may be more prone to DILI.Patients with NSAIDs have more severe liver damage in early stages of DILI,TNF-α and IL-6 may partake the inflammatory process of DILI.

Objective To understand the respiratory protection competency of staff in hospitals.Methods Staff from six hospitals of different levels and characteristics in Beijing were selected,including doctors,nurses,medical technicians,and servicers,to conduct knowledge assessment on respiratory protection competency.According to exposure risks of respiratory infectious diseases,based on actual cases and daily work scenarios,content of respira-tory protection competency assessment was designed from three aspects:identification of respiratory infectious di-seases,transmission routes and corresponding protection requirements,as well as correct selection and use of masks.The assessment included 6,6,and 8 knowledge points respectively,with 20 knowledge points in total,all of which were choice questions.For multiple-choice questions,full marks,partial marks,and no mark were given respective-ly if all options were correct,partial options were correct and without incorrect options,and partial options were correct but with incorrect options.Difficulty and discrimination analyses on question of each knowledge point was conducted based on classical test theory.Results The respiratory protection competency knowledge assessment for 326 staff members at different risk levels in 6 hospitals showed that concerning the 20 knowledge points,more than 60％participants got full marks for 6 points,while the proportion of full marks for other questions was relatively low.Less than 10％participants got full marks for the following 5 knowledge points:types of airborne diseases,types of droplet-borne diseases,conventional measures for the prevention and control of healthcare-associated infec-tion with respiratory infectious diseases,indications for wearing respirators,and indications for wearing medical protective masks.Among the 20 knowledge questions,5,1,and 14 questions were relatively easy,medium,and difficult,respectively;6,1,4,and 9 questions were with discrimination levels of ≥0.4,0.30-0.39,0.20-0.29,and ≤0.19,respectively.Conclusion There is still much room for hospital staff to improve their respiratory protection competency,especially in the recognition of diseases with different transmission routes and the indications for wearing different types of masks.

Objective To investigate the influence of the national volume-based procurement(NVBP)policy on the economy and use structure of anti-infective drugs in a general 3-A hospital,and to provide a reference for the standardization of clinical application management and policy implementation.Methods The price,defined daily doses(DDDs),average defined daily cost(DDDc),actual cost saving,substitution rate of selected drugs(SRSD)and avoidance rate of alternative drugs(ARAD)of anti-infective drugs before and after the implementation of 1-7 collection NVBP policy were analysed.Results The NVBP policy led to a＞70％reduction in the price of 70.73％of the hospital's target drugs,69.70％of the DDDs increased,81.82％of the DDDc decreased and 63.64％showed the relationship of"volume increase and price decrease".The average SRSD was 84.49％in the first cycle and 95.94％in the second cycle.The average actual cost saving in the first cycle was 474 100 yuan,with an average saving rate of 407.60％,and in the second cycle was 803 100 yuan,with an average saving rate of 1 257.04％,showing an increasing trend year by year.The consumption of alternative drugs increased by 53.85％in the first cycle and 66.67％in the second cycle,with the highest annual increase of 555.63％,and the average of 74.65％.Conclusion After the implementation of NVBP policy,selected drugs mainly replaced unselected drugs,and the cost of anti-infection treatment was greatly reduced.However,it was necessary to strengthen the control of alternative drugs,standardize the management of clinical application,carry out clinical comprehensive evaluation of selected drugs and real world research.

Objective To design a novel oxygenator to solve the existing problems of extracorporeal membrane oxygenation(ECMO)machine in high transmembrane pressure difference,low efficiency of blood oxygen exchange and susceptibility to thrombosis.Methods The main body of the oxygenator vascular access flow field was gifted with a flat cylindrical shape.The topology of the vascular access was modeled in three dimensions,and the whole flow field was cut into a blood inlet section,an inlet buffer,a heat exchange zone,a blood oxygen exchange zone,an outlet buffer and a blood outlet section.The oxygenator was compared with Quadrox oxygenator by means of ANSYS FLUENT-based simulation and prototype experiments.Results Simulation calculations showed the oxygenator designed was comparable to the clinically used ones in general,and gained advantages in transmembrane pressure difference,blood oxygen exchange and flow uniformity.Experimental results indicated that the oxygenator behaved better than Quadrox oxygenator in transmembrane pressure difference and blood oxygen exchange.Conclusion The oxygenator has advantages in transmem-brane pressure difference,temperature change,blood oxygen ex-change and low probability of thrombosis.[Chinese Medical Equipment Journal,2024,45(3):23-28]