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 study the effect of drinking carbohydrate drinks before cesarean section on mothers and neonates,and to explore the application value of drinking carbohydrate drinks before cesarean section.Methods The clinical data of 206 singleton women who underwent selective cesarean section in Obstetrics and Gynecology Hospital,Fudan University from Jun 2020 to Jun 2021 were retrospectively studied.Patients were divided into enhanced recovery after delivery(ERAD)group and control group according to whether drinking carbohydrate drinks before cesarean section.A retrospective cohort study was conducted to analyze the effect of preoperative carb drinks on preoperative fluid supplementation,postoperative rehabilitation and neonatal prognosis.Results Among patients who fasted for less than 12 hours,the ERAD group had a lower fluid supplementation rate and a smaller average fluid supplementation volume compared to the control group(P＜0.05).The ERAD group had a lower rate of prokinetic agent using after surgery(P＜0.05).Among women without a history of abdominal surgery,the ERAD group had less blood loss 24 hours after surgery(P＜0.05).There were no significant differences in postoperative fever rate,incidence of nausea and vomiting,time of first flatus,neonatal apgar score,exit observation room neonatal blood,and neonatal neonatal intensive care unit(NICU)admission rate between the two groups.Among newborns with high-risk factors for hypoglycemia,the ERAD group had lower enter observation room neonatal blood compared to the control group,and a higher incidence of hypoglycemia(P＜0.05).Conclusion Oral intake of carbohydrate drinks before cesarean section may be beneficial in reducing fluid supplementation before elective cesarean section,promoting postoperative gastrointestinal function recovery,and reducing postoperative bleeding.However,it may be related to the occurrence of neonatal hypoglycemia.

3ʹ-Hydroxy-4ʹ-methoxy-2-hydroxy-5-bromochalcone (hereinafter referred to as C13) is a novel chalcone derivative obtained in the process of structural modification of DHMMF, the antitumor active compound of Resina Draconis, in our laboratory. In this study, we investigated the effects of C13 on the proliferation and apoptosis of human gastric cancer HGC-27 and AGS cells and its potential mechanism of action. Firstly, through methyl thiazolyl tetrazolium (MTT), colony formation assay, and 5-ethynyl-2'-deoxyuridine (EdU) staining, we found that C13 inhibited the proliferation ability of human gastric cancer HGC-27 and AGS cells. Using flow cytometry and Western blot, it was found that C13 induced apoptosis in human gastric cancer HGC-27 and AGS cells, and up-regulated the protein level of cleaved poly ADP-ribose polymerase (cleaved-PARP). The results of RNA sequencing analysis showed that the Erb-b2 receptor tyrosine kinase 4/phosphoinositide 3-kinases/AKT (ErbB4/PI3K/AKT) signaling pathway may be involved in anti-gastric cancer activity of C13. Finally, the results of immunoblotting assay showed that C13 treatment down-regulated the protein levels of ErbB4 and phospho-ErbB4, as well as down-regulated the phosphorylation levels of PI3K and AKT in human gastric cancer HGC-27 and AGS cells, which verified the results from RNA-seq analysis. In conclusion, C13 inhibited the proliferation and induced apoptosis of human gastric cancer cells, which may be related to the down-regulation of ErbB4/PI3K/AKT signaling pathway. This study may provide a candidate drug for the treatment of gastric cancer.

Four pyrazines were isolated from the n-butanol fraction of Hypecoum erectum L. by using various chromatographic methods, including MCI gel, ODS, silica gel and semi-preparative HPLC. The structures of the isolated compounds were identified as hyperectpyrazin A (1), 1′S-(6-methylpyrazin-2-yl)-ethane-1′,2′-diol (2), 2-hydroxymethyl-6-methylpyrazin (3) and pyrazine-2-carboxylic acid (4) by spectroscopy methods (1D NMR, 2D NMR, UV, IR, MS, etc.). The absolute configuration of compound 2 was determined by using the Mo₂(OAc)₄ induced CD analysis for the first time. Compound 1 was a new compound, compounds 2-4 were isolated from H. erectum for the first time. Compounds 1-4 were evaluated for their inhibition against acetylcholinesterase and nitric oxide generation induced by lipopolysaccharide-RAW264.7 macrophage cells. At a concentration of 50 μmol·L^-1, compounds 2 and 4 displayed inhibitory effects on acetylcholinesterase with the inhibition rates of 44.40% and 43.99%, respectively.

Objective:To investigate the value of systemic inflammatory response syndrome (SIRS), pediatric sequential organ failure assessment (pSOFA) and pediatric critical illness score (PCIS) in predicting mortality of pediatric sepsis in pediatric intensive care units (PICU) from Southwest China.Methods:This was a prospective multicenter observational study. A total of 447 children with sepsis admitted to 12 PICU in Southwest China from April 2022 to March 2023 were enrolled. Based on the prognosis, the patients were divided into survival group and non-survival group. The physiological parameters of SIRS, pSOFA and PCIS were recorded and scored within 24 h after PICU admission. The general clinical data and some laboratory results were recorded. The area under the curve (AUC) of the receiver operating characteristic curve was used to compare the predictive value of SIRS, pSOFA and PCIS in mortality of pediatric sepsis.Results:Amongst 447 children with sepsis, 260 patients were male and 187 patients were female, aged 2.5 (0.8, 7.0) years, 405 patients were in the survival group and 42 patients were in the non-survival group. 418 patients (93.5%) met the criteria of SIRS, and 440 patients (98.4%) met the criteria of pSOFA≥2. There was no significant difference in the number of items meeting the SIRS criteria between the survival group and the non-survival group (3(2, 4) vs. 3(3, 4) points, Z=1.30, P=0.192). The pSOFA score of the non-survival group was significantly higher than that of the survival group (9(6, 12) vs. 4(3, 7) points, Z=6.56, P<0.001), and the PCIS score was significantly lower than that of the survival group (72(68, 81) vs. 82(76, 88) points, Z=5.90, P<0.001). The predictive value of pSOFA (AUC=0.82) and PCIS (AUC=0.78) for sepsis mortality was significantly higher than that of SIRS (AUC=0.56) ( Z=6.59, 4.23, both P<0.001). There was no significant difference between pSOFA and PCIS ( Z=1.35, P=0.176). Platelet count, procalcitonin, lactic acid, albumin, creatinine, total bilirubin, activated partial thromboplastin time, prothrombin time and international normalized ratio were all able to predict mortality of sepsis to a certain degree (AUC=0.64, 0.68, 0.80, 0.64, 0.68, 0.60, 0.77, 0.75, 0.76, all P<0.05). Conclusion:Compared with SIRS, both pSOFA and PCIS had better predictive value in the mortality of pediatric sepsis in PICU.

Objective To evaluate the effects of high-fat diet on the pharmacokinetics of metronidazole in Chinese healthy adult subjects.Methods This program is designed according to a single-center,randomized,open,single-dose trial.Forty-seven healthy subjects were assigned to receive single dose of metronidazole tablets 200 mg in either fasting and high-fat diet state,and blood samples were taken at different time points,respectively.The concentrations of metronidazole in plasma were determined by high performance liquid chromatography-mass spectromentry.Results The main pharmacokinetic parameters of metronidazole in fasting state and high-fat diet state were as follows:Cmax were(4 799.13±1 195.32)and(4 044.17±773.98)ng·mL-1;tmax were 1.00 and 2.25 h;t1/2 were(9.11±1.73)and(9.37±1.79)h;AUC0_t were(5.59±1.19)x 104 and(5.51±1.18)x 104 ng·mL-1·h;AUC0_∞ were(5.79±1.33)x 104 and(5.74±1.32)× 104 ng·mL-1·h.Compared to the fasting state,the tmaxof the drug taken after a high fat diet was delayed by 1.25 h(P＜0.01),Cmax,AUC0_t,AUC0-∞ were less or decreased in different degrees,but the effects were small(all P＞0.05).Conclusion High-fat diet has little effects on the pharmacokinetic parameters of metronidazole,which does not significantly change the degree of drug absorption,but can significantly delay the time to peak.

Objective To investigate the effects of palmatine on migration,invasion and epithelial mesenchymal transformation(EMT)in human oral cancer KB cells.Methods KB cells were divided into control group and palmatine-L,-M,-H groups,cultured with 0,4,8 and 16 μmol·L-1 palmatine.After incubation for 48 h,scratch assay was used to detect migration;Traswell assay was used to detect invasion;matrix metalloproteinase 2(MMP-2),MMP-9 and fibronectin(FN)contents were detected by enzyme-linked immunosorbent assay;the expression of Vimentin,N-cadherin and E-cadherin mRNA were detected by real-time quantitative polymerase chain reaction;the expression of Vimentin,N-cadherin,E-cadherin,Wnt3 and β-catenin protein were detected by Western blot.Results Cell mobility in control group and palmatine-L,-M,-H groups were(69.27±8.62)％,(52.94±4.49)％,(45.22±5.05)％and(37.63±4.88)％;the number of transmembrane cells were 197.33±20.26,125.33±12.01,97.00±9.17 and 62.67±7.51;the content of MMP-2 were(2.93±0.21),(1.49±0.13),(1.16±0.15)and(0.95±0.09)ng·mL-1;the content of MMP-9 were(3.51±0.36),(2.37±0.23),(2.06±0.35)and(1.72±0.16)ng·mL-1;the content of FN were(41.28±4.02),(24.03±3.17),(20.67±2.63)and(13.82±2.19)ng·mL-1;the above indexes in palmatine-L,-M,-H groups were compared with the control group,and the differences were statistically significant(P＜0.05,P＜0.01).The mRNA and protein expressions of Vimentin,N-cadherin and E-cadherin,and the expressions of Wnt3 and β-catenin protein in palmatine-L,-M,-H groups were statistically significant compared with those in control group(P＜0.05,P＜0.01).Conclusion Palmatine can inhibit the migration,invasion and EMT of human oral cancer KB cells,and its mechanism is related to the regulation of Wnt/β-catenin signaling pathway.

Radiation mainly comes from medical radiation,industrial radiation,nuclear waste and atmospheric ultraviolet radiation,etc.,radiation is divided into ionizing radiation and non-ionizing radiation.Studying the effects of ionizing and non-ionizing radiation on drug metabolism,understanding the absorption and distribution of drugs in the body after radiation and the speed of elimination under radiation conditions can provide reasonable guidance for clinical medication.This article reviews the effects of radiation on the pharmacokinetics of different drugs,elaborates the changes of different pharmacokinetics under radiation state,and discusses the reasons for the changes.

Objective:To explore the clinical outcome and applicability of the comb flap technique and stepwise design concept in plastic aesthetic and reconstructive surgery.Methods:The clinical data of patients who underwent plastic aesthetic and reconstructive surgery with the comb flap technique in Shanghai Ninth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine from January 2018 to December 2022 were retrospectively analyzed. The application of the comb flap technique follows the concept of stepwise design, that was, preoperative and intraoperative design and adjustment were carried out step by step and in sequence, and the design was combined with the surgical procedure. Its main operations included: an incision was designed along the edge of the target area, the tissue flap was widely separated at the base of the target area. The tissue flap was cut in sequence perpendicular to the cutting edge and temporarily sutured and fixed, the edge was cut and fixed. During the operation, the tension of the incision and the local appearance could be adjusted. The incisal edge was finely sutured, and the temporary suture was finally removed. The healing of surgical incision and complications were observed after the operation, and the facial recovery and surgical effect were followed up.Results:Six patients were enrolled, including 3 males and 3 females, aged from 2 to 58 years. One patient underwent upper eyelid tightening and lower eyelid blepharoplasty through subeyebrow incision. One patient underwent middle and lower face rhytidectomy. One patient underwent thick lip thinning and right facial liposuction. One patient underwent facial congenital melanocytic nevi resection. One patient underwent eyebrow congenital melanocytic nevus resection. One patient underwent facial flap repair. All patients had primary healing of incision, and no surgery-related complications occurred. All patients were followed up for 3 to 18 months, and all patients were satisfied with the surgical effect.Conclusion:The application of comb flap technique and stepwise design concept in plastic aesthetic and reconstructive surgery can delicately adjust the alignment of the incision margin, make the tension evenly distributed, and reduce the risk of scar formation and deformity after the operation. It has a wide range of clinical applications and good applicability.

Objective To investigate the effect of MALAT1 expressions on cell proliferation and apoptosis in astrocytes by regulating mitogen-activated protein kinase(MAPK)/extracellular signal-regulated kinase(ERK1,2)pathway.Methods The MALAT1 gene was knocked down and over-expressed in C8-D1A cells by lentiviral and plasmid vectors,respectively.The expressions of MALAT1,cell proliferation-related markers(Ki67,MCM2,PCNA)and apoptosis-related proteins(Caspase-3,Bax,Bcl-2)were detected by quantitative real-time polymerase chain reaction(qPCR).CCK-8 assay and flow cytometry were used for cell proliferation and apoptosis in C8-D1A cells.Immunofluorescence was adopted to detect the protein expressions of Caspase-3 and Ki67.Western blotting was used to detect the protein expressions of Caspase-3,Bax,Bcl-2,ERK1/2,p-ERK1/2,p38MAPK and p-p38MAPK.Results Compared with the control group,over-expressed MALAT1 inhibited cell proliferation and induced cell apoptosis in C8-D1A cells while the knockdown of MALAT1 significantly enhanced cell proliferation and anti-apoptotic ability in C8-D1A cells.The proportion of C8-D1A cells in G0/G1-phase and G2/M-phase was higher than in the control group as evidenced by flow cytometry,but was lower in S-phase.Meanwhile,data showed that Caspase-3 was increased while p-ERK1/2 was decreased in terms of protein levels.The mRNA expressions of Ki67 and PCNA were decreased.After knockdown of MALAT1,the proportion of C8-D1A cells in S-phase was higher,but was lower in G2/M-phase.The protein expressions of Caspase-3 and Bax decreased while those of p-ERK1/2 and p-p38MAPK increased.The mRNA expressions of Ki67,MCM2 and PCNA were increased.The differences were all statistically significant(P＜0.05).Conclusion MALAT1 promotes astrocyte apoptosis and inhibits proliferation by regulating the MAPK/ERK1,2 signaling pathway.