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 investigate the effect of quercetin(Que)on podocyte inflammatory injury and the under-lying mechanism.Methods MPC5 cells were divided into normal glucose group(NG),mannitol group(MA),high glucose group(HG)and high glucose+quercetin group(HG+Que).Cell proliferation and apoptosis were detected by CCK-8 and flow cytometry.The expression of SIRT1,STAT3,apoptosis-related proteins(Bax,Bcl-2,caspase-3)and pyroptosis pro-tein GSDME was detected by Western blot.The ex-pression levels of inflammatory factors(IL-6,TNF-α,IL-18,IL-1β)in cell supernatants were detected by ELISA.Then small interfering RNA technology was used to knockdown SIRT1 expression.To further eval-uate the biological significance of SIRT1 in response to high glucose and Que treatment,negative control group(HG+si-NC+Que)and SIRT1 interference group(HG+si-SIRT1+Que)were added in the presence of high glucose and Que.Results Compared with the high glucose group,40 μmol·L-1 Que could alleviate the apoptosis of MPC5 cells induced by high glucose,decrease the expression of apoptosis related protein Bax and caspase-3,as well as increase the expression of anti-apoptotic protein Bcl-2;ELISA results showed that Que could decrease the expression of TNF-α,IL-6,IL-1 β and IL-18 induced by high glucose.Mechanical-ly,Que could alleviate the inhibitory effect of high glu-cose on the expression of SIRT1,and further decrease the activation of STAT3 and N-GSDME,and inhibit pyroptosis.Compared with the si-NC group,si-SIRT1 group could reverse the protective effect of Que on the high glucose induced inflammatory damage of podo-cytes,the expression of apoptotic proteins Bax and caspase-3 increased,while the expression of anti-apop-totic protein Bcl-2 decreased.At the same time,the levels of inflammatory cytokines TNF-α,IL-6,IL-1 βand IL-18 in supernatants increased,and the expres-sion of STAT3 and N-GSDME increased.Conclusion Que could inhibit pyroptosis and relieve the inflam-matory damage of podocytes through SIRT1/STAT3/GSDME pathway.

Aim To study the effect of Guben Yanling pills on liver aging in aging mice and the related mech-anism.Methods The mice were randomly divided in-to blank control group,model group,vitamin E group(0.1 g·kg-1)and low,medium and high dose groups(0.59,1.17,2.34 g·kg-1)of Guben Yan-ling pills.The aging mouse model was established by subcutaneous injection of D-galactose(150 mg·kg-1)into the back of neck.At the same time of mod-eling,the corresponding drugs were given by gavage once a day for six weeks.The main organ indexes were calculated.HE staining was used to observe the mor-phology of liver tissue.Colorimetry was used to detect the activity of β-galactosidase in liver.ELISA was used to detect the content of TNF-α,IL-1 β,IL-6,IL-4,IL-10.Western blot was used to detect the protein relative expression level of IKKβ,Iκ Bα,NF-κB p65.Immunofluorescence was used to detect the expression level of NF-κB p65.Results Compared with the blank control group,the organ index of the brain,liv-er,kidney,spleen,and thymus in the model group decreased(P＜0.05,P＜0.01),the activity of β-galactosidase increased(P＜0.01),liver tissue mor-phology and structure were significantly damaged,the content of TNF-α,IL-1 β and IL-6 increased(P＜0.01),the content of IL-4 and IL-10 decreased(P＜0.01),the levels of IKKβ,NF-κB p65 in-creased(P＜0.01),the levels of IKBα decreased(P＜0.01),and the levels of NF-κB p65 in nucleus increased(P＜0.01).Compared with the model group,the organ indexes of brain,liver,kidney,spleen,and thymus in each dose group of Guben Yan-ling pills increased(P＜0.05,P＜0.01),the activity of β-galactosidase decreased(P＜0.01),the morpho-logical and structural damage of liver tissue was signifi-cantly improved,the content of TNF-α,IL-1 β and IL-6 decreased(P＜0.01),the content of IL-4 and IL-10 increased(P＜0.01),the levels of IKKβ,NF-κB p65 decreased(P＜0.01),the levels of IκBα in-creased(P＜0.01),and the levels of NF-κB p65 in nucleus decreased(P＜0.01).Conclusions Guben Yanling pills can antagonize liver aging in mice,and its mechanism may be related to inhibiting the activa-tion of NF-κB signaling pathway in liver,downregulat-ing downstream pro-inflammatory factor levels,upregu-lating anti-inflammatory factor levels,and alleviating inflammation in liver.

Objective To explore clinical effect of single small incision with honeycomb titanium plate in treating acute acromioclavicular dislocation.Methods The clinical data of 40 patients with acute acromioclavicular dislocation admitted from December 2019 to December 2021 were retrospectively analyzed and divided into two groups according to different surgical methods.Among them,20 patients were fixed with single small incision with honeycomb titanium plate(titanium plate group),including 11 males and 9 females,aged from 23 to 65 years old with an average of(47.40±12.58)years old;12 patients on the left side,8 patients on the right side;11 patients with type Ⅲ,3 patients with type Ⅳ,and 6 patients with type Ⅴ according to Rockwood classification.Twenty patients were fixed with clavicular hook plate(clavicular hook group),including 8 males and 12 females,aged from 24 to 65 years old with an average of(48.40±12.08)years old;12 patients on the left side,8 patients on the right side;10 patients with type Ⅲ,2 patients with type Ⅳ,and 8 patients with type V according to Rockwood classifica-tion.Operative time,incision length,intraoperative blood loss,hospital stay,visual analogue scale(VAS)and Constant-Murley score of shoulder joint function were compared between two groups.Anteroposterior radiographs of the affected shoulder joint were recorded before,immediately and 6 months after surgery,and the coracoclavicular distance was measured and compared.Results Both groups of patients were successfully completed operation without serious complications.All patients were fol-lowed up for 6 to 15 months with an average of(11.9±4.8)months.There were no incisional infection,internal plant fracture or failure,bone tunnel fracture and other complications occurred.The incision length of titanium plate group(35.90±3.14)mm was significantly shorter than that of clavicular hook group(49.30±3.79)mm(P＜0.05).There were no significant difference in operative time,intraoperative blood loss and hospital stay between two groups(P＞0.05).At 1 and 3 months after operation,VAS of titanium plate group was lower than that of clavicular hook group(P＜0.05).Connstant-Murley scores in titanium plate group at 1,3 and 6 months after operation were(86.80±1.36),(91.60±2.32)and(94.90±2.22),respectively;and in clavicular hook group were(78.45±5.47),(85.55±2.01)and(90.25±1.92),which were higher than that of clavicular hook group(P＜0.05).There was no significant difference in coracoclavicular distance between two groups immediately and 6 months after op-eration(P＞0.05).Conclusion For the treatment of acute acromioclavicular joint dislocation,single small incision combined with honeycomb titanium plate have advantages of shorter incision,fast recovery of shoulder joint function without the second operation,and has good satisfaction of patient.

Objective To investigate the factors influencing prognosis in patients with acute myocardial infarction complicated with cardiogenic shock undergoing primary percutaneous coronary intervention(PPCI).Methods Patients with acute myocardial infarction complicated with cardiogenic shock who underwent PPCI at our hospital between January 2015 and December 2019 were enrolled.Clinical baseline characteristics,coronary angiography and PCI-related parameters,and mechanical support information were collected.The patients were followed up for one year and divided into survival and death groups based on their survival status within one year.Differences in various factors between the two groups were compared.Results A total of 40 patients were enrolled,including 26 in the survival group and 14 in the death group.There were no differences in baseline data,diagnosis,risk factors,and comorbidities between the two groups.The survival group had a lower heart rate and higher blood pressure trend at admission compared to the death group.Myocardial enzymes were significantly lower in the survival group compared to the death group(median CK peak:496.00(198.25,2 830.00)U/L vs.3 040.00(405.75,5 626.53)U/L,P=0.003;median CK-MB peak:52.65(31.75,219.50)U/L vs.306.00(27.25,489.63)U/L,P=0.006).When comparing coronary angiography and PCI-related indicators between the two groups,the survival group had a higher rate of complete revascularization compared to the control group(53.85％vs.21.43％,P=0.048).The survival group had a higher proportion of extracorporeal membrane oxygenation(ECMO)combined with intra-aortic balloon pump(IABP)support compared to the control group[38.46％vs.7.14％,P=0.034].Conclusions Survival in patients with acute myocardial infarction complicated with cardiogenic shock undergoing PPCI is associated with lower level of myocardial enzymes,ECMO combined with IABP support and complete revascularization.

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in tertiary hospitals in major regions of China in 2022.Methods Clinical isolates from 58 hospitals in China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2022 Clinical &Laboratory Standards Institute(CLSI)breakpoints.Results A total of 318 013 clinical isolates were collected from January 1,2022 to December 31,2022,of which 29.5％were gram-positive and 70.5％were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species(excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi)was 28.3％,76.7％and 77.9％,respectively.Overall,94.0％of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 90.8％of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis showed significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 94.2％in the isolates from children and 95.7％in the isolates from adults.The resistance rate to carbapenems was lower than 13.1％in most Enterobacterales species except for Klebsiella,21.7％-23.1％of which were resistant to carbapenems.Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.1％to 13.3％.The prevalence of meropenem-resistant strains decreased from 23.5％in 2019 to 18.0％in 2022 in Pseudomonas aeruginosa,and decreased from 79.0％in 2019 to 72.5％in 2022 in Acinetobacter baumannii.Conclusions The resistance of clinical isolates to the commonly used antimicrobial agents is still increasing in tertiary hospitals.However,the prevalence of important carbapenem-resistant organisms such as carbapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a downward trend in recent years.This finding suggests that the strategy of combining antimicrobial resistance surveillance with multidisciplinary concerted action works well in curbing the spread of resistant bacteria.

Objective:To explore the potential action mechanism of Huotu Jiji Pellets(HJP)in the treatment of erectile dys-function(ED)based on network pharmacology and molecular docking.Methods:We identified the main effective compounds and active molecular targets of HJP from the database of Traditional Chinese Medicine Systems Pharmacology(TCMSP)and Integrative Pharmacology-Based Research Platform of Traditional Chinese Medicine(TCMIP)and the therapeutic target genes of ED from the data-bases of Genecards.Then we obtained the common targets of HJP and ED using the Venny software,constructed a protein-protein in-teraction(PPI)network of HJP acting on ED,and screened out the core targets with the Cytoscape software.Lastly we performed GO functional enrichment and KEGG pathway enrichment analyses of the core targets followed by molecular docking of HJP and the core targets using Chem3D and AutoDock Tools and QuickVina-W software.Results:A total of 64 effective compounds,822 drug-related targets,1 783 disease-related targets and 320 common targets were obtained in this study.PPI network analysis showed that the core targets of HJP for ED included ESR1,HSP90AA1,SRC,and STAT3.GO functional enrichment analysis indicated the involvement of the core targets in such biological processes as response to xenobiotic stimulus,positive regulation of kinase activity,and positive regu-lation of MAPK cascade.KEGG pathway enrichment analysis suggested that PI3K-Akt,apoptosis,MAPK,HIF-1,VEGF,autophagy and other signaling pathways may be related to the mechanism of HJP acting on ED.Molecular docking prediction exhibited a good doc-king activity of the key active molecules of HJP with the core targets.Conclusion:This study showed that HJP acted on ED through multi-components,multi-targets and multi-pathways,which has provided some evidence and reference for the clinical treatment and subsequent studies of the disease.

Objective:To investigate the clinical and genetic characteristics of a male carrier of exceptional complex chromo-some rearrangement(CCR)and the outcome of preimplantation genetic testing for chromosomal structural rearrangement(PGT-SR).Methods:Using the modified high resolution G banding technique and whole-genome low-coverage sequencing(WGLCS),we analyzed the cellular karyotype and molecular karyotype of a male carrier of CCR,performed an analysis of the single-sperm chromosome copy number and conducted PGT-SR for the patient by next-generation sequencing(NGS).In addition,we reviewed the literature on repor-ted male carriers of CCRs and summarized their normal/balanced sperm ratios and PGT-SR outcomes.Results:The karyotype of the patient was 46,XY,der(5)inv(5)(q14.3q23.2)t(5;14;11)(q23.2;q31.1;q21),der(11)t(5;14;11);der(14)t(5;14;11),with the translocation breakpoints located in the intergenic region.Single-sperm sequencing revealed 20.0%(7/35)of normal haploids in the male's spermatozoa,and the results PGT-SR showed a proportion of 25.0%(4/16)of normal/balanced embryos.After thawing and transferring of 2 euploid blastocysts,a healthy male infant was successfully delivered.Conclusion:The proportion of normal hap-loids in the spermatozoa of male CCR carriers may be higher than theoretically predicted,and PGT-SR can effectively improve the preg-nancy outcome in male CCR carriers and provide valuable data for genetic counseling.

Objective To design an intelligent arm band-type multi physiological parameter monitoring device to collect vital sign signals at real time such as ECG,oxygen saturation,blood pressure,body temperature and position/motion.Methods The monitoring device had its hardware components composed of a main control module,sensor acquisition modules,a Bluetooth communication module,a data display and storage module and peripheral control modules.A STM32L452 SCM was used as the main control module,the sensor acquisition modules included an ECG and body temperature module,an acceleration module,a blood oxygen module and a blood pressure module,and the peripheral control modules were comprised of a key control module and a power management module.The software components consisted of a piece of lower computer software and a piece of upper computer software.The lower computer software was written in C language with Keil MDK embedded development platform,and the upper computer software was developed based on Lab VIEW platform.The monitoring device developed was tested for stability in wireless transmission and data storage and performance in vital sign signal acquisition so as to verify its functions and performance.Results The test results showed the monitoring device gained advantages in transmission reliability,low power consumption,portability and wearability;the monitoring device proved to have high accuracies with the absolute values of the measurement errors of temperature,heart rate,oxygen saturation,systolic blood pressure and diastolic blood pressure being 0.08 ℃,2 times/min,1％,4 mmHg(1 mmHg=133.32 Pa)and 5 mmHg,respectively.Conclusion The monitoring device behaves well in low size,weight and power consumption,which can be used for multi physiological signal monitoring and meet the requirements for wearability.[Chinese Medical Equipment Journal,2024,45(5):34-42]

Objective To design a portable intelligent cleaner for medical lumen instruments to enhance cleaning efficiency.Methods The portable intelligent cleaner had a box-body shape and a shell made of 304 stainless steel,which was composed of a circuit control board,a micro pump,lithium batteries,a charging interface,a rinse tube and connectors.The circuit control board used a STM32G030C8T6 integraged circuit,which was equipped with a countdown digital tube to display the time left for cleaning;the micro pump and lithium batteries were placed at the inner wall of the box bottom,the charging interface and water inlet/outlet inteface were put on the outside of the front wall of the box bottom,the water inlet/outlet interface was connected with a silicon rinse tube linked to an adapter at its distal end,and the adapters with different calibers were compatible with sizes of medical lumen instruments.Totally 9 672 pieces of lumen instruments received by some hospital's disinfection supply center from May to October 2021 were divided into 2 groups with the convenience sampling method,with 4 836 pieces in each group.The odd-numbered instruments were enrolled into a control group and cleaned with an ultrasonic cleaner and a lumen brush,and the even-numbered instruments were included into an experimental group and cleaned conventionally after pretreatment by the intelligent cleaner.The two groups were compared in terms of eaning efficiency and satisfaction.Results Testing by visual inspection,magnifying glass with light source and white stripe method showed that the experimental group behaved better than the control group in the cleaning qualification rate,whose satisfaction rate(100％)was also higher than that of the control group(86.53％),with all the differences being statistically significant(P＜0.05).Conclusion The portable cleaner with easy operation enhances the cleaning quality and efficiency for medical lumen instruments.[Chinese Medical Equipment Journal,2024,45(10):114-117]