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.

Objective:The clinical data of prenatal stillbirth were analyzed in order to increase the understand-ing of the causes of stillbirth.Methods:Prenatal stillbirth cases that terminated pregnancy in Nanjing Drum Tower Hospital,Affiliated Hospital of Medical School,Nanjing University from January 2018 to December 2022 were col-lected,and the distribution characteristics of clinical data and the stillbirth causes were analyzed.The causes of death were classified according to the standards developed by the Stillbirth Collaborative Research Network(SCRN)in the United States,and they were divided into clear cause-of-death group and unknown cause-of-death group.The different characteristics of the two groups were compared and analyzed.Results:There were 210 ca-ses of prenatal stillbirth during the study period,and 104 cases met the inclusion criteria.Among them,33 cases(31.7%)had autopsy results,39 cases(37.5%)had genetic results,and 75 cases(72.1%)had placental pathol-ogy.According to the classification of SCRN standard,55 cases(52.9%)were probably related to the cause of death,33 cases(31.7%)were classified as possible,13 cases(12.5%)were probably unrelated,and 3 cases(2.9%)could not be attributed to the cause of death,that is,84.6%(88 cases)in the clear cause of death group and 15.4%(16 cases)in the unknown cause of death group.The rate of placental pathological examination in the clear cause of death group was significantly higher than that in the unknown cause of death group(78.4%).In the classification of causes of death,placental pathological changes accounted for the largest proportion,account-ing for 26.9%(28 cases),followed by pregnancy complications accounting for 25.0%(26 cases),and 15.4%of the cases were still unexplained.Conclusions:Placental pathology is of great significance for clarifying the cause of stillbirth.It is feasible to use SCRN to classify the etiology of stillbirth.Pathological placental conditions account for a relatively high proportion in the classification of stillbirth causes.It is recommended that each case of stillbirth placenta should undergo pathological examination.

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.

Background Cognitive behavioral therapy(CBT)is a widely used and empirically supported psychotherapy method.In recent years,the localization of CBT related to culture has received increasing attention from Chinese scholars.However,there is still a lack of systematic research on the localization of CBT using idioms as materials.Objective To explore whether idioms reflect the mutual influence between the two core therapeutic elements of CBT(cognition and emotion)and to use them as CBT treatment tools among college students,so as to provide references for the localization of CBT.Methods Using the Xinhua Idiom Dictionary(second edition)published by the Commercial Press,a three-round manual screening method was used to select idioms that reflected the mutual influence between cognition and emotion in CBT.Based on the selected idioms,a survey questionnaire titled"survey on idiom understanding level"was developed.From August to October,2022,stratified sampling was conducted among college students from different majors and universities,and 815 valid questionnaires were obtained through the Questionnaire Star platform.By analyzing the understanding of each idiom among college students,idioms that could be used as CBT treatment tools were identified.Results In the Xinhua Idiom Dictionary(second edition),there were 13 idioms that reflected the influence of cognition on emotion and 5 idioms that reflected the influence of emotion on cognition.12 idioms could be used as CBT treatment tools,including 8 idioms that reflected the influence of cognition on emotion and 4 idioms that reflected the influence of emotion on cognition.Conclusion There may be idioms that reflect the mutual influence between the two core therapeutic elements of CBT(cognition and emotion)and these idioms can be attempted as a therapeutic tool for CBT among college students.

Objective:To establish a cell line stably expressing the transient receptor potential melastatin 2(TRPM2)channel for screening TRPM2 inhibitors based on PiggyBac transposition system.Methods:A plasmid PiggyBac-human TRPM2(pPB-hTRPM2)eukaryotic expression vector was constructed using PiggyBac transposition system.The plasmid and a helper plasmid were co-transfected into HEK293T cells to express TRPM2,which was identified by fluorescence and patch-clamp assays.The high throughput screening performance was assessed with the Z'factor.Calcium imaging and patch clamp techniques were employed to assess the initial activity of eleven compound molecules,confirming the inhibitory effects of the primary molecules on TRPM2.The protective effect of the screened compounds on damaged cells was validated using the oxygen-glucose deprivation/reperfusion(OGD/R)injury model and CCK-8 kit.The level of cellular reactive oxygen species(ROS)was detected by flow cytometry.The neuroprotective effects of the compounds were evaluated using a transient middle cerebral artery occlusion(tMCAO)mouse model.Results:The HEK293T cells transfected with pPB-hTRPM2-EGFP showed high TRPM2 expression.Puromycin-resistant cells,selected through screening,exhibited robust fluorescence.Whole-cell patch results revealed that induced cells displayed classical TRPM2 current characteristics comparable to the control group,showing no significant differences(P＞0.05).With a Z'factor of 0.5416 in calcium imaging,the model demonstrated suitability for high-throughput screening of TRPM2 inhibitors.Calcium imaging and electrophysiological experiments indicated that compound 6 significantly inhibited the TRPM2 channel.Further experiments showed that 1.0 μmol/L of compound 6 enhanced cell viability(P＜0.05)and reduced the level of ROS(P＜0.05)of SH-SY5Y under OGD/R injury.0.3 and 1.0 mg/kg of compound 6 reduced the cerebral infarction volume in tMCAO mice(both P＜0.05).Conclusions:A stable TRPM2 gene expressing cell line has been successfully established using PiggyBac gene editing in this study.TRPM2 channel inhibitors were screened through calcium imaging and patch clamp techniques,and an inhibitor compound 6 was identified.This compound can alleviate cell damage after OGD/R by reducing cellular ROS levels and has a protective effect against cerebral ischemia-reperfusion injury in mice.

Objective To investigate the efficacy of utilizing Kaneka dual lumen microcatheter in combination with anchored balloon in treatment of bifurcation lesions in elderly patients with ra-dial artery 6 F catheter.Methods A retrospective analysis was performed on 168 patients(≥60 years)receiving bifurcation treatment with a 6 F catheter via the radial artery at the Heart Center of our hospital from January 2020 to January 2023.According to application of dual lumen micro-catheters and anchoring balloon technology or not,they were assigned into an anchoring group(81 cases old)and a control group(87 cases).A comparison was made between the two groups in terms of features of coronary artery disease,operation procedure,and MACE.Multivariate logistic regression analysis was employed.Results Lower incidence of dissection,shorter operation time,less X-ray exposure dose,and decreased contrast agent dosage were observed in the anchoring group when compared with the control group(P＜0.05,P＜0.01).There was no statistical differ-ence in the MACE incidence between the two groups(4.9％vs 8.0％,P＞0.05).The side branch dissection and final TIMI grade＜3 of side branch flow were independent risk factors for postop-erative MACE in elderly patients with bifurcation lesions after surgery(P＜0.05,P＜0.01).Conclusion Kaneka dual lumen microcatheter combined with anchored balloon technology via radial artery 6 F catheter has the advantages in effectively shorting operation time,minimizing X-ray exposure,reducing contrast agent usage,and diminishing the incidence of side branch dis-section in treatment of bifurcation lesions in elderly patients undergoing surgical treatment.

Objective:To investigate the surgical situations and perioperative outcome of pancreaticoduodenectomy in Jiangsu Province and the influencing factors for postoperative 90-day mortality.Methods:The retrospective case-control study was conducted. The clinicopathological data of 2 886 patients who underwent pancreaticoduodenectomy in 21 large tertiary hospitals of Jiangsu Quality Control Center for Pancreatic Diseases, including The First Affiliated Hospital of Nanjing Medical University, from March 2021 to December 2022 were collected. There were 1 732 males and 1 154 females, aged 65(57,71)years. Under the framework of the Jiangsu Provincial Pancreatic Disease Quality Control Project, the Jiangsu Quality Control Center for Pancreatic Diseases adopted a multi-center registration research method to establish a provincial electronic database for pancrea-ticoduodenectomy. Observation indicators: (1) clinical characteristics; (2) intraoperative and post-operative conditions; (3) influencing factors for 90-day mortality after pancreaticoduodenectomy. Measurement data with skewed distribution were represented as M( Q1, Q3) or M(IQR), and comparison between groups was conducted using the Mann-Whitney U test. Count data were expressed as absolute numbers or constituent ratio, and comparison between groups was conducted using the chi-square test, continuity correction chi-square test and Fisher exact probability. Maximal Youden index method was used to determine the cutoff value of continuous variables. Univariate analysis was performed using the corresponding statistical methods based on data types. Multivariate analysis was performed using the Logistic multiple regression model. Results:(1) Clinical characteristics. Of the 2 886 patients who underwent pancreaticoduodenectomy, there were 1 175 and 1 711 cases in 2021 and 2022, respectively. Of the 21 hospitals, 8 hospitals had an average annual surgical volume of <36 cases for pancreaticoduodenectomy, 10 hospitals had an average annual surgical volume of 36-119 cases, and 3 hospitals had an average annual surgical volume of ≥120 cases. There were 2 584 cases performed pancreaticoduodenectomy in thirteen hospitals with an average annual surgical volume of ≥36 cases, accounting for 89.536%(2 584/2 886)of the total cases. There were 1 357 cases performed pancrea-ticoduodenectomy in three hospitals with an average annual surgical volume of ≥120 cases, accounting for 47.020%(1 357/2 886) of the total cases. (2) Intraoperative and postoperative conditions. Of the 2 886 patients, the surgical approach was open surgery in 2 397 cases, minimally invasive surgery in 488 cases, and it is unknown in 1 case. The pylorus was preserved in 871 cases, not preserved in 1 952 cases, and it is unknown in 63 cases. Combined organ resection was performed in 305 cases (including vascular resection in 209 cases), not combined organ resection in 2 579 cases, and it is unknown in 2 cases. The operation time of 2 885 patients was 290(115)minutes, the volume of intra-operative blood loss of 2 882 patients was 240(250)mL, and the intraoperative blood transfusion rate of 2 880 patients was 27.153%(782/2 880). Of the 2 886 patients, the invasive treatment rate was 11.342%(327/2 883), the unplanned Intensive Care Unit (ICU) treatment rate was 3.087%(89/2 883), the reoperation rate was 1.590%(45/2 830), the duration of postoperative hospital stay was 17(11)days, the hospitalization mortality rate was 0.798%(23/2 882), and the failure rate of rescue data in 2 083 cases with severe complications was 6.529%(19/291). There were 2 477 patients receiving postoperative 90-day follow-up, with the 90-day mortality of 2.705%(67/2477). The total incidence rate of complication in 2 886 patients was 58.997%(1 423/2 412). The incidence rate of severe complication was 13.970%(291/2 083). The comprehensive complication index was 8.7(22.6) in 2 078 patients. (3) Influencing factors for 90-day mortality after pancreaticoduodenectomy. Results of multivariate analysis showed that age ≥ 70 years, postoperative invasive treatment, and unplanned ICU treatment were independent risk factors for 90-day mortality after pancreaticoduodenectomy ( odds ratio=2.403, 2.609, 16.141, 95% confidence interval as 1.281-4.510, 1.298-5.244, 7.119-36.596, P<0.05). Average annual surgical volume ≥36 cases in the hospital was an independent protective factor for 90-day mortality after pancreaticoduodenectomy ( odds ratio=0.368, 95% confidence interval as 0.168-0.808, P<0.05). Conclusions:Pancreaticoduodenectomy in Jiangsu Province is highly con-centrated in some hospitals, with a high incidence of postoperative complications, and the risk of postoperative 90-day mortality is significant higher than that of hospitallization mortality. Age ≥ 70 years, postoperative invasive treatment, and unplanned ICU treatment are independent risk factors for 90-day motality after pancreaticoduodenectomy, and average annual surgical volume ≥36 cases in the hospital is an independent protective factor.

Objective To explore the effect of a R language-based autoregressive integrated moving average(ARIMA)model for predicting the consumption of medical consumables.Methods The monthly consumption data of a certain type of pre-filled flush syringe from July 2018 to June 2023 was selected as the sample data,which underwent smoothness test and difference operation with R language.An ARIMA model was established and the optimal model was determined according to the Akaike and Bayesian information criteria.The corresponding data of the third quarter of 2023 was used as the validation set to predict the consumption,and the prediction result was compared with the actual values to evaluate the prediction effect of the ARIMA model.Results The ARIMA model with the best fitting was ARIMA(0,1,1)(1,0,0)12,all the predicted data were within 95％confidence interval,and its mean absolute percentage error MAPE was 9.92％.P-value proved to be higher than 0.05 when the residual series were tested using the Ljung-Box statistics,which meant the prediction result was satisfactory.Conclusion The R language-based ARIMA model behaves well in predicting the consumption of medical consumables,and provides references for demand planning,budgeting,purchasing and management of medical consumables.[Chinese Medical Equipment Journal,2024,45(10):84-87]

Objective:To observe the effect of human mesenchymal stem cells(hMSCs)conditioned medium(CM)co-cultured with the human liposarcoma SW872 cells on the proliferation and migration of the tumor cells,and to discuss the effect of hMSCs CM on the liposarcoma cells and the possible mechanism.Methods:The hMSCs were cultured in vitro and transfected with either lentiviral vector control shNS(control group)or lentiviral shRNA targeting Yes-associated protein(YAP)(shYAP-hMSCs group)by lentiviral methods.The expression levels of YAP mRNA and protein in the hMSCs in various groups were detected by real-time fluorescence quantitative PCR(RT-qPCR)and Western blotting methods.The CM was then harvested.The SW872 cells were cultured in vitro and divided into control group(normal culture),hMSCs CM group,and shYAP-hMSCs CM group.The proliferation activities of the cells in various groups were detected by CCK-8 assay;the apoptotic rates of the cells in various groups were detected by flow cytometry;the scratch healing rates of the cells in various groups were detected by cell scratch assay;the expression levels of YAP,matrix metallopeptidase-9(MMP-9),and cyclin D1 proteins in the cells in various groups were detected by Western blotting method.Results:Compared with control group,the expression levels of YAP mRNA and protein in the cells in shYAP-hMSCs group were decreased(P＜0.01),indicating the successful establishment of a stable transfected cell line.The CCK-8 assay results showed that compared with control group,the proliferation activity of the cells in hMSCs CM group was increased(P＜0.05),and the proliferation activity of the cells in shYAP-hMSCs CM group was decreased(P＜0.01).The flow cytometry results showed that compared with control group,there was no significant change in the apoptotic rate of the cells in hMSCs CM group(P＞0.05),while the apoptotic rate of the cells in shYAP-hMSCs CM group was increased(P＜0.01).The cell scratch assay results showed that compared with control group,the scratch healing rate of the cells in hMSCs CM group was increased(P＜0.05),and the scratch healing rate of the cells in shYAP-hMSCs CM group was decreased(P＜0.01).The Western blotting results showed that compared with control group,there were no significant differences in the expression levels of YAP,MMP-9,and cyclin D1 proteins in the cells in hMSCs CM group(P＞0.05),while the expression levels of YAP,MMP-9,and cyclin D1 proteins in the cells in shYAP-hMSCs group were decreased(P＜0.05 or P＜0.01).Conclusion:The hMSCs regulate the proliferation and migration of the human liposarcoma SW872 cells,and its mechanism may be related to the expression of YAP.

Objective To understand the change in distribution and antimicrobial resistance of bacteria isolated from blood specimens of Hunan Province,and provide for the initial diagnosis and treatment of clinical bloodstream infection(BSI).Methods Data reported from member units of Hunan Province Antimicrobial Resistance Survei-llance System from 2012 to 2021 were collected.Bacterial antimicrobial resistance surveillance method was imple-mented according to the technical scheme of China Antimicrobial Resistance Surveillance System(CARSS).Bacteria from blood specimens and bacterial antimicrobial susceptibility testing results were analyzed by WHONET 5.6 soft-ware and SPSS 27.0 software.Results A total of 207 054 bacterial strains were isolated from blood specimens from member units in Hunan Province Antimicrobial Resistance Surveillance System from 2012 to 2021,including 107 135(51.7％)Gram-positive bacteria and 99 919(48.3％)Gram-negative bacteria.There was no change in the top 6 pathogenic bacteria from 2012 to 2021,with Escherichia coli(n=51 537,24.9％)ranking first,followed by Staphylococcus epidermidis(n=29 115,14.1％),Staphylococcus aureus(n=17 402,8.4％),Klebsiella pneu-moniae(17 325,8.4％),Pseudomonas aeruginosa(n=4 010,1.9％)and Acinetobacter baumannii(n=3 598,1.7％).The detection rate of methicillin-resistant Staphylococcus aureus(MRSA)decreased from 30.3％in 2015 to 20.7％in 2021,while the detection rate of methicillin-resistant coagulase-negative Staphylococcus(MRCNS)showed an upward trend year by year(57.9％-66.8％).No Staphylococcus was found to be resistant to vancomy-cin,linezolid,and teicoplanin.Among Gram-negative bacteria,constituent ratios of Escherichia coli and Klebsiella pneumoniae were 43.9％-53.9％and 14.2％-19.5％,respectively,both showing an upward trend(both P＜0.001).Constituent ratios of Pseudomonas aeruginosa and Acinetobacter baumannii were 3.6％-5.1％and 3.0％-4.5％,respectively,both showing a downward trend year by year(both P＜0.001).From 2012 to 2021,resistance rates of Escherichia coli to imipenem and ertapenem were 1.0％-2.0％and 0.6％-1.1％,respectively;presenting a downward trend(P＜0.001).The resistant rates of Klebsiella pneumoniae to meropenem and ertapenem were 7.4％-13.7％and 4.8％-6.4％,respectively,presenting a downward trend(both P＜0.001).The resistance rates of Pseudomonas aeruginosa and Acinetobacter baumannii to carbapenem antibiotics were 7.1％-15.6％and 34.7％-45.7％,respectively.The trend of resistance to carbapenem antibiotics was relatively stable,but has de-creased compared with 2012-2016.The resistance rates of Escherichia coli to the third-generation cephalosporins from 2012 to 2021 were 41.0％-65.4％,showing a downward trend year by year.Conclusion The constituent ra-tio of Gram-negative bacillus from blood specimens in Hunan Province has been increasing year by year,while the detection rate of carbapenem-resistant Gram-negative bacillus remained relatively stable in the past 5 years,and the detection rate of coagulase-negative Staphylococcus has shown a downward trend.