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 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.

Using methylated pyrroloxicam as a starting material and following the principles of drug design such as bioisosterism and active site binding,we designed and synthesized ten structurally novel target compounds,whose structures were characterized by 1H NMR and MS analysis.The in vitro antitumor activity of these title compounds was evaluated by measuring their inhibitory activity against pancreatic cancer cells Capan-1,leukemia cells L1210,and human liver cancer cells SMMC-7721.The results showed that compound 6f(IC50=4.8±0.5 μmol/L)exhibited good inhibitory activity against Capan-1 pancreatic cancer cells,that compound 6b(IC50=2.6±0.3 μmol/L)showed good inhibitory activity against L1210 leukemia cells,and that compound 6c(IC50=2.1±0.2 μmol/L)displayed good inhibitory activity against SMMC-7721 human liver cancer cells.These preliminary results from the antitumor activity experiments suggest that the introduction of benzothiazine derivatives plays a certain role in enhancing the antitumor activity of this class of compounds.

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.

Objective To explore the molecular mechanism of Gualou Guizhi decoction which regulates the interferon regulator factor 5(IRF5)signaling pathway to inhibit M1 type microglia activation and reduce the inflammatory response to protect damaged nerve cells.Methods Microglia(BV2)cells were randomly divided into BV2-control,BV2-model,BV2-experimental-L,-M,-H groups.The BV2-control group was given routine culture;the BV2-model group used 100 ng·mL-1 lipopolysaccharide(LPS)to stimulate BV2 which establish an inflammatory model;the BV2-experimental-L,-M,-H groups were cultured in 50,100,200 μg·mL-1 GLGZD and 100 ng·mL-1 LPS.The HT22 cells were divided into the HT-22-blank group,HT-22-model group,HT-22-control group and HT-22 experimental group.HT-22-blank group were conventional culture;HT-22-model group were oxygen glucose deprivation was performed for 2 h,then the complete medium was replaced for 24 h;HT-22-control group were after 2 h of oxygen glucose deprivation,the 100 ng·mL-1 LPS conditioned medium was replaced and incubated for 24 h;HT-22-experimental group were after 2 h of oxygen glucose deprivation,the 200 μg·mL-1 GLGZD conditioned medium was added for 24 h.Interleukin-12(IL-12)and IL-23 were detected by enzyme-linked immunosorbent assay(ELISA);the protein of IRF5,cluster differentiation 16(CD1 6)and MHC class Ⅱ(MHC-Ⅱ)was detected by Western blot;the expression of the synaptic marker protein class Ⅲ β-Tubulin(Tuj-1)was observed by immunofluorescence.Results IL-12 contents in the BV2-control,BV2-model and BV2-experimental-L,-M,-H groups were(2.62±1.02),(10.67±3.22),(6.87±1.61),(3.96±1.22)and(3.36±1.04)pg·mL-1;IL-23 contents were(20.40±2.04),(77.08±3.25),(76.28±3.75),(63.96±4.94)and(54.48±3.34)pg·mL-1;relative expression levels of IRF5 protein were 0.80±0.41,2.22±0.69,1.11±0.11,0.92±0.39 and 0.65±0.29;relative expression levels of CD16 protein were 0.69±0.45,1.91±0.52,1.42±0.22,1.04±0.15 and 0.67±0.30;relative expression levels of MHC-Ⅱ protein were 0.89±0.27,1.96±0.19,1.34±0.38,1.15±0.19 and 0.68±0.24.BV2-experimental-M,-H groups were compared with the BV2-model group,the differences were statistically significant(all P＜0.05).The Tuj-1 protein expression levels were 28.85±6.69,14.44±1.98,7.75±1.12 and 20.05±3.54,determined in the HT22-blank,HT22-model,HT22-control and HT22-experimental groups.The HT22-experimental group was compared with the HT22-control group,the difference was statistically significant(P＜0.05).Conclusion GLGZD may reduces the activation of microglia M1 phenotype through IRF5 signaling pathway,and then inhibits inflammatory response to protect damaged nerve cells.

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 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 explore the therapeutic effect and mechanism of pressing and rubbing method on myofascial pain syndrome(MPS)rats.Methods A total of 12 rats were randomly selected from 60 rats as the normal group,and the remaining rats were used to construct the MPS model by blunt strike combined with centrifugal exercise.Then 48 successfully modeled rats were randomly divided into model group,pressing and rubbing method group,pressing and rubbing method + Dantrolene[ryanodine receptor(RyR)inhibitor]group,pressing and rubbing method + normal saline group,with 12 rats in each group.The mechanical pain threshold was measured by von-Frey method.Detection of soft tissue tension,electromyography was performed;the ultrastructure of the pain point tissue was observed by transmission electron microscopy.The content of calcium ion(Ca2+)in the tissue of trigger point was detected by colorimetry.The protein expressions of dihydropyridine receptor(DHPR)α1,RyR and acetylcholinesterase(AChE)in the pain points of rats were detected by Western Blot.Results Compared with the normal group,the mechanical pain threshold,soft tissue tension in trigger point and the protein expressions of DHPRα1,RyR and AChE in the model group were decreased and the Ca2+ + content was increased(all P＜0.05),and the peak potential with higher amplitude was observed in the electromyogram.The ultrastructure of the trigger point tissue was damaged.Compared with the model group,the mechanical pain threshold,soft tissue tension of trigger point and the protein expressions of DHPRα1,RyR and AChE in the trigger point tissue of the rats in the pressing and rubbing method group and the pressing and rubbing method + normal saline group were increased,and the Ca2+ content was decreased(all P＜0.05),the electromyography was restored to be stable,the ultrastructural damage of the trigger point tissue was alleviated.Compared with the pressing and rubbing method group,the mechanical pain threshold,soft tissue tension of trigger point and protein the expressions of DHPRα1,RyR and AChE in the trigger point tissue of the rats in the pressing and rubbing method + Dantrolene group were decreased,and the Ca2+ content was increased(all P＜0.05),the electromyogram showed electrical activity changes,the ultrastructure of the trigger point tissue was damaged.Conclusion The pressing and rubbing method may improve MPS in rats by activating the DHPR/RyR signaling pathway.

Objective To measure the distance between the lateral compression Ⅱ(LC-Ⅱ)screw guide needle and the surrounding important structures around the anterior inferior iliac spine in pelvic fractures and to locate the needle point,so as to provide anatomical reference for clinical nail placement.Methods Totally 40 adult gross specimens of embalming were implanted with LC-Ⅱ screw guide needle under the surveillance of C-arm machine,and the specimens were dissected.The shortest distance between the insertion point and the lateral femoral cutaneous nerve,femoral nerve,femoral artery,femoral vein,anterior superior iliac spine and inguinal ligament was measured.The triangle was constructed between the insertion point,anterior superior iliac spine and inguinal ligament,and the exact location of the entry point was calculated.Results The average distance between the insertion point of the male needle and the femoral vein was(50.67±7.29)mm＞the anterior superior iliac spine(43.83±7.58)mm＞the femoral artery(38.35±6.63)mm＞the femoral nerve(31.17±1.67)mm=the inguinal ligament(28.69±6.59)mm＞the lateral femoral cutaneous nerve(7.98±3.81)mm.The mean distance between the insertion point of the female needle and the anterior superior iliac spine was(45.28±7.07)mm=femoral vein(43.72±6.89)mm＞femoral artery(33.76±6.33)mm＞femoral nerve(25.66±6.46)mm=inguinal ligament(23.22±5.00)mm＞lateral femoral cutaneous nerve(8.97±4.76)mm.The projection distance of the entry point was 31.77 mm for men and 38.41 mm for women.The Angle b was 42.81°for men and 31.71° for women.Conclusion The lateral femoral cutaneous nerve is most vulnerable to injury when LC-Ⅱ screw is inserted,and the risk of injury has nothing to do with sex.The insertion point positioning method a and b made LC-Ⅱ screw placement quickly,safely and accurately,and reduced fluoroscopy time and frequency.

The current research status of different structures,driving modes and training modes of hand rehabilitation robots at home and abroad was introduced.The disadvantages of the existing hand rehabilitation robots were analyzed.It's pointed out hand rehabilitation robots in the future would involve in the combination of rigid and flexible wearing,new intelligent driving mode and multi-mode rehabilitation training.[Chinese Medical Equipment Journal,2024,45(11):88-96]