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.

Objectives To investigate the relationship between self-reported occupational noise exposure and levels of plasma inflammatory cytokines in asthmatic patients. Methods A total of 910 adult asthmatic patients were selected as the study subjects, and their occupational noise exposure history and other related information were collected. The peripheral blood samples were collected from the patients, and the expression levels of plasma soluble CD14 (sCD14), complement factor D (CFD), Eotaxin-11 (CCL11), and IL-9 were determined. The relationship between self-reported occupational noise exposure and the expression levels of the four inflammatory cytokines in patients’ plasma were analyzed using multiple linear regression models. The interactions between confounding factors and self-reported occupational noise exposure were further analyzed by interaction analysis. Results The plasma CCL11, sCD14 and CFD expressions in asthmatic patients with self-reported occupational noise exposure were significantly higher than those in patients without the exposure (P<0.05). After adjusting for confounding factors, compared with patients reporting no occupational noise exposure, the plasma CFD expression was increased by 0.17 (95% CI: 0.02, 0.31) natural logarithm units in patients with self-reported occupational noise exposure. During remission, the levels of plasma CCL11 and sCD14 in asthmatic patients with self-reported occupational noise exposure were increased by 0.27 (95% CI: 0.05, 0.49) and 0.22 (95% CI: 0.02, 0.41) natural logarithm units, respectively, when compared with patients without the exposure. Interaction analysis showed that self-reported occupational noise exposure had significant multiplicative interaction with smoking or pet ownership on plasma CCL11 or CFD expressions in asthmatic patients (all P<0.05). Conclusion Self-reported occupational noise exposure is significantly associated with increased expression levels of plasma CFD, CCL11, and sCD14 in adult asthmatic patients.

ObjectiveTo investigate the acute effects of compound air pollution on children’s respiratory function. MethodsUsing panel group study design， 223 students in five classes of grade 4 from two primary schools （a， b） in Xuhui and Hongkou districts of Shanghai were randomly selected to measure pulmonary function and exhaled nitric oxide （FeNO）. The first three tests were carried out from May to June in 2020， and the fourth test was carried out from September to December in 2021. At the same time， the daily and hourly mean values of PM_2.5， PM₁₀， SO₂， NO₂， O₃ and CO was collected from the nearby air quality monitoring points of the two schools during the same period ， as well as meteorological monitoring data （temperature， humidity， wind speed and atmospheric pressure）. The linear mixed effect model was used to analyze the effects of air pollution on pulmonary function and respiratory inflammation in the summer. ResultsThe results of single pollutant model showed that PM_2.5， PM_10， SO₂ and NO₂ were positively correlated with FeNO， and the effect was reflected in lag0， lag1 and lag3 （P<0.05）. PM_2.5， PM₁₀ and NO₂ were negatively correlated with the changes of lung function FEF_25%， FEF_50%， FEF_75%， FeF_25%-75%， PEF， FVC， FEV1 and FEV1/FVC， and the effect was reflected in lag0 to lag3 days （P<0.05）. The results of the dual pollutant model showed that the concentration changes of SO₂ and NO₂ were significantly correlated with the decrease of FEV1 when combined with O₃ or PM_2.5 （P<0.01）， and the concentration changes of PM_2.5 was significantly correlated with the increase of FeNO when O₃， SO₂ and NO₂ were combined respectively （P<0.01）. The effects of the dual pollutant model were greater than the effect of PM_2.5 single pollutant model. ConclusionThe health effects of different air pollutants on children’s respiratory tract function indexes in summer are different. The combined effects of two pollutants on the lung function of children increased to different degrees. Although air pollution is light in summer， it still has an impact on children’s respiratory tract function index and inflammation index， and the combined effect of dual pollutants is more significant than that of single pollutant.

Objective:To analyze retinal vascular parameters and distribution characteristics in Chinese population via the fully automated quantitative measurement of retinal vascular morphological parameters based on artificial intelligence technology.Methods:A cross-sectional study was performed.A total of 1 842 patients without fundus diseases who visited Beijing Tongren Hospital from January 2011 to December 2021 were included.Standardized questionnaires, blood draws and ophthalmologic examinations of enrolled subjects were conducted.Color fundus photographs centered on the optic disk of one eye of patients were collected, and a deep learning-based semantic segmentation network ResNet101-Unet was used to construct a vascular segmentation model for fully automated quantitative measurement of retinal vascular parameters.The main measurement indexes included retinal vascular branching angle, vascular fractal dimension, average vascular caliber, and average vascular tortuosity.To compare different retinal parameters between sexes, the correlation between the above parameters and ocular factors such as best corrected visual acuity, intraocular pressure, and axial length, as well as systemic factors such as sex, age, hypertension, diabetes mellitus, and cardiovascular disease was analyzed.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of Beijing Tongren Hospital, Capital Medical University (No.20001220). Written informed consent was obtained from each subject.Results:The model established in this study achieved an accuracy over 0.95 for both vascular and optic disk segmentation.The vascular branching angle, vascular fractal dimension, average vascular caliber, and average vascular tortuosity were (51.023±11.623)°, 1.573(1.542, 1.592), 64.124(60.814, 69.053)μm, (0.001 062±0.000 165)°, respectively.Compared with females, males had larger vascular branching angle, smaller average vascular caliber and smaller vascular tortuosity, and the differences were statistically significant (all at P<0.05). The average vascular caliber increased by 1.142 μm in people with cardiovascular disease compared to people without cardiovascular disease ( B=1.142, P=0.029, 95% CI: 0.116-2.167). The average vascular tortuosity was positively correlated with hypertension ( B=3.053×10 -5, P=0.002, 95% CI: 1.167×10 -5-4.934×10 -5) and alcohol consumption ( B=1.036×10 -5, P=0.014, 95% CI: 0.211×10 -5-1.860×10 -5) and negatively correlated with hyperlipidemia ( B=-2.422×10 -5, P=0.015, 95% CI: -4.382×10 -5-0.462×10 -5). For each 1-mm increase in axial length, there was a decrease of 0.004 in vessel fractal dimension ( B=-0.004, P<0.001, 95% CI: -0.006--0.002), a decrease of 0.266 μm in the average vessel caliber ( B=-0.266, P=0.037, 95% CI: -0.516--0.016), and a decrease of -2.45×10 -5° in the average vessel tortuosity ( B=-2.45×10 -5, P<0.001, 95% CI: -0.313×10 -5--0.177×10 -5). For each 1.0 increase in BCVA, there was an increase of 3.992° in the vascular branch angle ( B=3.992, P=0.004, 95% CI: 1.283-6.702), an increase of 0.090 in vascular fractal dimension ( B=0.090, P<0.001, 95% CI: 0.078-0.102) and a decrease of 14.813 μm in the average vascular diameter ( B=-14.813, P<0.001, 95% CI: -16.474--13.153). Conclusions:A model for retinal vascular segmentation is successfully constructed.Retinal vessel parameters are associated with sex, age, systemic diseases, and ocular factors.

Objective To analyze the changes of vitamin D in children with Henoch-Schonlein purpura(HSP).Methods 130 children with HSP from Kunming Children's Hospital between July 2022-July 2023 were selected as the study subjects and 100 healthy children were selected during the same period as the control group.The blood samples were collected from the children with HSP and the healthy children.The content of vitamin D was measured by Kunming Kingmed Institute for Clinical Laboratory.Results The content of 25(OH)D in children with HSP was lower than that in healthy children,and the difference was statistically significant(P<0.01).The proportion of vitamin D insufficiency in children with HSP was higher than that in healthy children,and the difference was statistically significant(P<0.01).Conclusion The children with HSP are prone to vitamin D insufficiency.Vitamin D supplementation may provide a new method for the treatment of HSP.

Objective To observe the role of dried tangerine peel in Yigong Powder improves iron metabolism and promotes red blood cell generation in anemia of chronic disease (ACD).Methods With a two-by-two factorial design,the Yigong Powder was divided into dried tangerine peel and Chenpi absent Decoction. According to the random number table method,32 zymosan-induced generalized inflammation (ZIGI) mice were randomly divided into the model group,the dried tangerine peel group,the Chenpi absent Decoction group,and the Yigong Powder group. The dried tangerine peel group,Chenpi absent Decoction group and the Yigong Powder group were given dried tangerine peel(3.083 g/kg),Chenpi absent Decoction(12.33g/kg),and Yigong Powder(15.413g/kg)by gavage to the corresponding group of mice. The model group was given an equal amount of physiological saline by gavage,and treated continuously for 7 days. After the completion of administration,the body weight of each group of mice was recorded. The hemoglobin content of each group of mice was detected using a fully automatic cell counter,the serum iron content was detected using colorimetry,the serum ferritin content was detected using enzyme-linked immunosorbent assay (ELISA),and the spleen index was calculated. The liver tissue inflammatory factors interleukin-1β (IL-1β),interleukin-6 (IL-6),tumor necrosis factor-α (TNF-α),interferon-γ (IFN-γ),interleukin-4 (IL-4),and interleukin-10 (IL-10) levels were detected using Luminex method. The mRNA expressions of liver tissue hepcidin gene (HAMP) and membrane iron transporter ( Fpn) were detected using real-time fluorescence PCR method. Results Dried tangerine peel and Chenpi absent Decoction both showed interactive effects in regulating hemoglobin,serum iron,serum ferritin content,improving spleen index,and regulating the mRNA expressions of HAMP,Fpn,as well as IL-1β and IFN-γ (P<0.05). Compared with the model group,dried tangerine peel significantly increased hemoglobin,serum iron content,and Fpn mRNA expression in ZIGI model mice,while decreasing ferritin content,spleen index,HAMP mRNA expression,and the levels of IL-1β,IL-6,TNF-α,and IFN-γ (P<0.05). Chenpi absent Decoction significantly increased serum iron content and Fpn mRNA expression in ZIGI model mice,while reducing spleen index,ferritin content,HAMP mRNA expression,and the levels of IL-1β and IFN-γ、IL-4 (P<0.05). Conclusion The effects of dried tangerine peel on inflammatory factors (IL-6 and TNF-α) and Fpn may play a key role in the improvement effects of Yigong Powder on ACD and iron metabolism.

The assessment of adverse drug events is an important basis for clinical safety evaluation and post-marketing risk control of drugs,and its causality assessment is gaining increasing attention.The existing methods for assessing the causal relationship between drugs and the occurrence of adverse reactions can be broadly classified into three categories:global introspective methods,standardized methods,and probabilistic methods.At present,there is no systematic introduction of the operational details of the various methods in the domestic literature.This paper compares representative causality assessment methods in terms of definition and concept,methodological steps,industry evaluation and advantages and disadvantages,clarifies the basic process of determining the causality of adverse drug reactions,and discusses how to further improve the adverse drug reaction monitoring and evaluation system,with a view to providing a reference for drug development and pharmacovigilance work in China.

Objective To observe the clinical efficacy and safety of ticagrelor tablets combined with atorvastatin calcium tablets in the treatment of cerebral thrombosis.Methods The patients with cerebral thrombosis were divided into control group and treatment group according to cohort methods.Two groups were given basic therapy.On the basic therapy,control group was given atorvastatin calcium 20 mg per time,once a day,orally;on the basic of control group,the treatment group received ticagrelor 90 mg per time,twice a day,orally.Two groups were treated for 4 months.The clinical efficacy,nerve function,blood viscosity,platelet parameters,brain injury markers and adverse drug reactions were compared between two groups.Results Treatment and control groups enrolled 119 and 117 cases,respectively.After treatment,the total effective rates of treatment and control groups were 91.60％(109 cases/119 cases)and 82.05％(96 cases/117 cases)with significant difference(P＜0.05).After treatment,the scale scores of treatment and control groups were(5.47±0.82)and(6.51±0.96)points;the plasma viscosity levels were(1.35±0.21)and(1.62±0.24)mPa·s,whole blood high shear viscosity levels were(3.67±0.51)and(4.01±0.59)mPa·s;the whole blood low shear viscosity levels were(6.12±0.93)and(7.05±1.07)mPa·s;the platelet adhesion rates were(30.52±3.81)％and(36.21±4.02)％;the mean platelet volumes were(12.75±1.86)and(15.42±2.06)fL;the carboxy-terminal hydrolase of ubiquitin levels were(0.39±0.06)and(0.51±0.07)μg·L-1;the key protein antigen-5 of aging levels were(90.76±12.23)and(81.64±11.95)μg·L-1;and the differences were statistically significant between two groups(all P＜0.05).The adverse drug reactions of two groups were nausea,vomiting,bleeding,abdominal pain and diarrhea.The total incidences of adverse drug reactions in treatment and control groups were 5.04％and 4.27％,without significant difference(P＞0.05).Conclusion Ticagrelor tablets combined with atorvastat in calcium tablets have a significant clinical efficacy in the treatment of patients with cerebral thrombus,which can significantly improve the neurological function,blood viscosity,brain injury markers,and platelet parameters of patients,without increasing the incidence of adverse drug reactions.

Hypertension and osteoporosis(OP)are common diseases in middle-aged and elderly people,and the number of patients with both diseases has gradually increased in recent years.Because the onset of the disease is hidden,it is easy to cause fractures and serious complications of heart,brain and kidney in the later stage,which not only seriously damages the quality of life of patients,but also increases the difficulty of clinical treatment.Therefore,it is particularly necessary to strengthen the research on this disease.More and more studies have found that the disorder of intestinal flora will lead to the occurrence of OP,while the intestinal flora of patients with hypertension is obviously out of balance.Therefore,this paper thinks that intestinal flora may be the key influencing factor of hypertension complicated with OP,and the imbalance of intestinal flora will lead to the imbalance of short-chain fatty acid metabolism,immune inflammatory reaction and increased sympathetic nerve activity,thus causing the imbalance of bone homeostasis and promoting the occurrence of OP.Therefore,it is suggested that regulating intestinal flora may be a new way to intervene hypertension complicated with OP.

Objective To evaluate the characteristics of the mass balance and pharmacokinetics of[14 C]birociclib in Chinese male healthy volunteers after a single oral administration.Methods This study used a 14 C labeled method to investigate the mass balance and biological transformation of birociclib in human.Subjects were given a single oral dose of 360 mg/50 pCi of[14 C]birociclib suspension after meals.The blood,urine,and fecal samples were collected at specified time points/intervals after administration.The radiation levels of 14 C labeled birociclib-related compounds in the blood,plasma,urine,and feces were analyzed using liquid scintillation counting.In addition,a combination of high-performance liquid chromatography and on-line/off-line isotope detectors was used to obtain radioactive isotope metabolite spectra of plasma,urine,and fecal samples,and high-resolution mass spectrometry was used to identify the main metabolites.Results A total of 6 healthy male subjects were enrolled in this study.The median peak time of radioactive components in plasma was 5.00 h and the average terminal elimination half-life was 43.70 h after administration.The radioactive components were basically excreted and cleared from the body within 288.00 hours after administration,and average cumulative recovery rate of radioactive drugs was(94.10±8.19)％.The radioactive drugs were mainly excreted through feces,accounting for(84.60±7.10)％of the dose of radioactive drugs administered.Urine was the secondary excretory pathway,accounting for 9.41％of the dose of radioactive drugs administered.Metabolic analysis indicated that the prototype drug was the main radioactive components in plasma samples.The main metabolites in plasma were RM4(XZP-5286),RM6(XZP-3584),and RM7(XZP-5736).The drugs were mainly cleared from the body in the form of prototype drugs and metabolites.In addition to prototype drugs,a total of 9 metabolites were identified and analyzed in plasma,urine,and fecal samples,all of which were phase 1 metabolites.The main metabolic and clearance pathways of drugs in the body were deethylation,diisopropylat ion,oxidation,etc.Conclusion After a single oral administration of[14C]birociclib suspension to healthy subjects,it was mainly cleared from the body in the form of prototype drugs and metabolites,with feces as the main excretory pathway and urine as the secondary excretory pathway.Drugs mainly undergo metabolic reactions in the body,such as deethylation,diisopropylation,and oxidation.The subjects were well tolerance after administration.