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 investigate an outbreak of acute gastroenteritis at a vocational and technical school in Shaanxi Province in 2024, ao as to provide the reference for the handling of school outbreaks. Methods: The conducted case searches, individual case investigations, and on-site hygienic investigations were established in accordance with the Guidelines on outbreak investigation, prevention and control of Norovirus infection (2015). The potential risk factors were analyzed by case-control study. Anal swab samples from cases and all canteen staff, as well as environmental swab samples were collected to detect common intestinal pathogens. All reserved food samples in canteen were collected to test for common pathogenic bacteria. Results: From October 26 to November 5, 2024, a cumulative total of 53 cases were reported, with an attack rate of 1.47%. The main clinical symptoms included vomiting (83.02%), abdominal pain (56.60%), diarrhea (30.19%), and fever (26.42%). The epidemic curve suggested an intermittent common-source outbreak, with no obvious clustering characteristics in terms of the population and spatial distribution of cases. The case-control analysis revealed that having dinner at the rice-with-dishes-on-top stall on the first floor of the canteen on October 28 was a risk factor for illness (OR=11.025, 95%CI: 2.186-55.601). GⅡ norovirus was detected as positive in anal swab samples from 6 cases and 2 asymptomatic infected canteen staff, as well as in 3 environmental swab samples from the rice-with-dishes-on-top stall. The test results for common pathogenic bacteria in the reserved food samples were all negative. Conclusions This outbreak was caused by an acute gastroenteritis epidemic induced by GⅡ norovirus infection, with a transmission pattern consistent with an intermittent homologous outbreak. The possible source of infection was asymptomatic infected canteen staff mainly through foodborne trasmission, and having meals at the rice-with-dishes-on-top stall was the primary risk factor for this outbreak.

Aim To investigate the effects of ber-bamine on behavioral changes in LPS-induced chronic neuroinflammation model mice and the related mecha-nisms.Methods By injecting lipopolysaccharide in-traperitoneally for seven days in a row,berbamine was given intraperitoneally as a treatment;the behavioral studies of mice in each group were identified;Nissen staining was used to observe the changes in the patho-logical morphology of the mouse hippocampus and the expression levels of inflammation-related proteins.These procedures established a mouse neuroinflamma-tion model.Results The number of neurons in the model group's hippocampal CA1 and CA3 regions was significantly smaller than that in the control group.In the water maze experiment,as the number of training days grew,the model group's escape latency increased and its retention time in the target quadrant dropped.The immobilization period of the model group mice in-creased during the forced swimming exercise.Serum levels of inflammatory factors such as IL-1β,IL-6,and TNF-α levels were also higher.The hippocampus tis-sue of the mice in the model group had higher levels of NLRP3,ASC,caspase-1,IL-18,ROCK1,ROCK2 ex-pression,and RHOA.When compared to the model group,the administration of berbamine was a therapy intervention.In the meantime,with the number of training days increased,the target quadrant lag time increased and the escape latency gradually decreased.Additionally,the model group's mice spent less time resting during forced swimming,and the serum inflam-matory factors TNF-α,IL-1β,and IL-6 decreased in mouse hippocampal tissues.Lastly,the expression lev-els of NLRP3,caspase-1,ASC,IL-1β,ROCK1,ROCK2,and RHOA all decreased in mouse hippocam-pal tissue.Conclusions The mechanism of action of berbamine,which improves lipopolysaccharide-induced depressive-like behaviors and modifies learning memory in mice,may include the NLRP3 and RHOA/ROCK signaling pathways.

Aim To explore the effects of Huannao Yicong decoction(HYD)on the learning and memory ability and brain iron metabolism in APP/PS1 mice and the correlation of HAMP knockout mice and APP/PS1 double transgenic model mice.Methods The ex-periment was divided into five groups,namely,HAMP-/-group(6-month HAMP gene knockout mice),APP/PS1 group(6-month APP/PS1-double-transgenic mice),HAMP-/-+HYD,APP/PS1+HYD,and negative control group(6-month C57BL/6J mice),with six mice in each group.The dose was ad-ministered(13.68 g·kg-1 weight),and the other groups received distilled water for gavage once a day for two months.After the administration of the drug,the mice in each group were tested for learning and memory in the Morris water maze;Biochemical detec-tion was performed to detect iron ion content in each mouse brain;Western blot and RT-qPCR were carried out to analyze hippocampal transferrin(TF),transfer-rin receptor1(TFR1),membrane iron transporter1(FPN1)divalent metal ion transporter 1(DMT1)and β-amyloid protein(Aβ)protein and mRNA expression levels in each group.Results Compared with the normal group,both HAMP-/-mice and APP/PS1 mice had reduced the learning and memory capacity,in-creased iron content in brain tissue,Aβ protein ex-pression increased in hippocampus of HAMP-/-group and APP/PS1 group mice(P＜0.01),the protein and mRNA expression of TF,TFR1 and DMT1 increased in hippocampal tissues of HAMP-/-and APP/PS1 groups(P＜0.01),and the FPN1 protein and mRNA expres-sion decreased(P＜0.01).Compared with the HAMP-and APP/PS1 groups,respectively,HAMP-/-+HYD group and APP/PS1+HYD group had improved learning and memory ability,decreased iron content,decreased Aβ protein expression(P＜0.01),decreased TF,TFR1,DMT1 protein and mR-NA expression(P＜0.01),and increased expression of FPN1 protein and mRNA(P＜0.01).Conclusions There is some association between HAMP-/-mice and APP/PS1 mice,HYD can improve the learning and memory ability of HAMP-/-and APP/PS1 mice and reduce the Aβ deposition.The mechanism may be related to the regulation of TF,TFR1,DMT1,FPN1 expression and improving brain iron overload.

Aim To investigate the regulatory mecha-nism of arrhythmia of sodium channel ubiquitination af-ter MI and to study the electrophysiological remodeling mechanism of lncRNA-CCRR after MI for the preven-tion and treatment of arrhythmia after MI.Methods LncRNA-CCRR transgenic mice and C57BL/6 mice injected with lncRNA-CCRR overexpressed adeno-asso-ciated virus were used.Four weeks after infection,the left anterior descending branch of the coronary artery was ligated for 12 h to establish a mouse acute myocar-dial infarction model,and the incidence of arrhythmia was detected by programmed electrical stimulation.Ln-cRNA-CCRR overexpression/knockdown adeno-associ-ated virus and negative control were transfected into neonatal mouse cardiomyocytes(NMCMs),and the model was prepared by hypoxia for 12 h.LncRNA-CCRR expression was detected by FISH,Nav1.5 and UBA6 protein and Nav.1.5 mRNA expression were de-tected by Western blot and real-time quantitative poly-merase chain reaction(qRT-PCR),Nav1.5 and UBA6 expressions were detected by immunofluores-cence,and the relationship between lncRNA-CCRR and UBA6 was detected by RIP.INa current density af-ter CCRR overexpression and knockdown was detected by Whole-cell clamp patch.Results In MI mice,the expression of lncRNA-CCRR decreased,the incidence of arrhythmia increased,the expression of CCRR and Nav1.5 mRNA was down-regulated,the protein ex-pression of Nav1.5 was down-regulated,and the pro-tein expression of UBA6 was up-regulated compared with sham group.Overexpression of CCRR could re-verse the above changes.AAV-CCRR could reverse the down-regulated CCRR and Nav1.5 mRNA levels af-ter hypoxia,and improve the expression of Nav1.5 and UBA6 protein.The direct relationship between ln-cRNA-CCRR and UBA6 was identified by RIP analy-sis.The INa density increased after transfection with AAV-CCRR.The INa density decreased after transfec-tion with AAV-si-CCRR.Conclusions The expres-sion of lncRNA-CCRR decreases after MI,and ln-cRNA-CCRR can improve arrhythmia induced by MI by inhibiting UBA6 to increase the protein expression level of Nav1.5 and the density of INa.

Objective To establish the finite element model of spinal canal reconstruction and internal fixation,analysis influence of spinal canal reconstruction and internal fixation on spinal stability,and verify the effectiveness and reliability of spinal canal reconstruction and internal fixation in spinal canal surgery.Methods A 30-year-old male healthy volunteer with a height of 172 cm and weight of 75 kg was selected and his lumbar CT data were collected to establish a finite element model of normal lumbar Lo3-L,and the results were compared with in vitro solid results and published finite element analysis results to verify the validity of the model.They were divided into normal group,laminectomy group and spinal canal reconstruction group according to different treatment methods.Under the same boundary fixation and physiological load conditions,six kinds of ac-tivities were performed,including forward bending,backward extension,left bending,right bending,left rotation and right rota-tion,and the changes of range of motion(ROM)of L3-L4,L4-L5 segments and overall maximum ROM of L3-L5 were analyzed under the six conditions.Results The ROM displacement range of each segment of the constructed L3-L5 finite element model was consistent with the in vitro solid results and previous literature data,which confirms the validity of the model.In L3-L4,ROM of spinal canal reconstruction group was slightly increased than that of normal group during posterior extension(＞5％dif-ference),and ROM of other conditions was similar to that of normal group(＜5％difference).ROM in laminectomy group was significantly increase than that in normal group and spinal canal reconstruction group under the condition of flexion,extension,left and right rotation.In L4-L5,ROM in spinal canal reconstruction group was similar to that in normal group(＜5％differ-ence),while ROM in laminectomy group was significantly higher than that in normal group and spinal canal reconstruction group(＞5％difference).In the overall maximum ROM of L3-L5,spinal canal reconstruction group was only slightly higher than normal group under the condition of posterior extension(＞5％difference),while laminectomy was significantly higher than normal group and spinal canal reconstruction group under the condition of anterior flexion,posterior extension,left and right rotation(＞5％difference).The changes of each segment ROM and overall ROM of L3-L5 showed laminectomy group＞spinal canal reconstruction group＞normal group.Conclusion Laminectomy could seriously affect biomechanical stability of the spine,but application of spinal canal reconstruction and internal fixation could effectively reduce ROM displacement of the responsi-ble segment of spine and maintain its biomechanical stability.

Objective To preliminarily investigate the related factors influencing the size of vestibular schwannomas.Methods The clinical data of patients with vestibular schwannomas who underwent retrosigmoid approach surgery at the department of neurosurgery of First Affiliated Hospital of Xinjiang Medical University from June 2013 to June 2023 were retrospectively analyzed.The tumor size of the patients was evaluated based on their preoperative imaging data.Univariate and multiple linear regression analyses were performed to explore the factors affecting the size of vestibular schwannomas.Results The tumor size of patients was ranging from 0.63 to 6.60 cm,with a median size of 2.97(2.20,3.80)cm.Univariate analysis showed that gender(P=0.010),ethnicity(P=0.001),age(P=0.049)and cystic solid tumor(P<0.001)were related to the size of vestibular schwannomas.Large-sized vestibular schwannomas were most commonly cystic-solid,and small and medium-sized vestibular schwannomas were most commonly solid.BMI,surgical side and place of residence were not correlated with the size of vestibular schwannomas(P>0.05).Multiple linear regression results showed that male(B=0.390,P=0.001)and Uyghur(B=0.611,P<0.001)patients were more likely to develop large tumors;with every 1-year increase in age,the maximum diameter of the tumor was reduced by an average of 0.011 cm(B=-0.011,P=0.027).Conclusion The gender,age,and ethnicity of patients are correlated with the size of vestibular schwannomas,and male,Uyghur,or younger patients were at higher risk of developing larger vestibular schwannomas.

Objective To analyze the clinical characteristics of patients with acute esophageal injuries in order to improve clinicians'diagnosis and treatment of such diseases.Methods The general data and treatment methods of 61 patients with acute esophageal injury from January 2013 to March 2023 were retrospectively analyzed.Results Majority of the patients with esophageal and cardia mucosal tear syndrome were male(72.2%),age(52.04±17.96)years,triggering factor was gastroscopy in 29 patients(53.7%),and vomiting of blood and black stools was the main clinical manifestation(63.0%),the average length of hospital stay was(6.39±3.53)d and 13(24.1%)patients had anaemic complications,blood transfusion was given to 8 patients(14.8%),39 patients(72.2%)were discharged after conservative treatment with transfusion,and only 15 patients(27.8%)required endoscopic hemostasis.1 case of esophageal hematoma combined with esophageal cardia mucosal tear syndrome was an elderly male patient with a history of hypertension,cerebral infarction,and long term use of oral aspirin,complicated by severe anemia,who was given desiprofloxacin to stop the hemostasis endoscopically,the total length of hospital stay was 22 d.4 patients with esophageal hematoma were young and middle-aged males,2 patients had a predisposing factor of poor diet prior to the onset of the disease,2 patients presented with vomiting of blood,1 with chest pain and 1 with a foreign body sensation in the throat,2 patients were discharged with endoscopic intervention,and the remaining 2 patients were discharged after conservative treatment.2 patients with spontaneous esophageal rupture were young and middle-aged males,clinical manifestations were chest tightness or retrosternal discomfort,and one patient had esophageal rupture with left-sided liquid pneumothorax,esophageal rupture repair+pleural adhesion branding+open thoracic hemostasis+intrathoracic foreign body removal was performed,and an esophageal stent was placed endoscopically after the operation,and the patient was discharged from the hospital after 52 d,in another case,the patient's esophageal fistula was small,and a three-lumen nutrient tube was placed under gastroscopic guidance,the patient's esophagus recovered well after 7 d,and the patient was discharged from the hospital.Conclusion Acute esophageal injury is a clinical emergency,among them,esophageal hematoma and spontaneous esophageal rupture are relatively rare.Prompt endoscopic clot removal is a viable option for patients with ruptured esophageal hematomas who have failed conservative treatment,and patients with spontaneous esophageal rupture who have surgically placed esophageal stents have good mucosal recovery.Clinicians need to be vigilant for patients with esophageal injuries that are associated with anemia,or even require blood transfusion,should make a clear diagnosis at an early stage,with timely endoscopic or surgical intervention to avoid progression of the disease.

Objective:To investigate two cases of rare pathogenic genes,initiation codon mutations in HBA2 gene,combined with Southeast Asian deletion and their family members to understand the relationship of HBA2:c.2T＞C and HBA2:c.2delT mutations with clinical phenotype.Methods:The peripheral blood of family members was obtained for blood cell analysis and capillary electrophoresis hemoglobin analysis.Gap-PCR and reverse dot blotting(RDB)were used to detect common types of mutations in α-thalassaemia gene.Sanger sequencing was used to analyze HBA1 and HBA2 gene sequence.Results:Two proband genotypes were identified as--SEA/αα with HBA2:c.2T＞C and--SEA/αα with HBA2:c.2delT.HBA2:c.2T＞C/WT and HBA2:c.2delT/WT was detected in family members.They all presented with microcytic hypochromic anemia.Conclusion:When HBA2:c.2T＞C and HBA2:c.2delT are heterozygous that can lead to static α-thalassemia phenotype,and when combined with mild α-thalassemia,they can lead to the clinical manifestations of hemoglobin H disease.This study provides a basis for genetic counseling.

Objective:To explore the effect of heterozygous deletion of histone methyltransferase Kmt2c gene on the hematological system of mice.Methods:CRISPR/Cas9 technology was used to construct mice model of Kmt2c heterozygous deletion(Kmt2c+/-)and the changes of whole blood cell count in mice were continuously monitored by blood routine test.The clonal expansion ability of bone marrow cells was explored by colony formation assay in vitro and the proportion of primitive hematopoietic cells,including long-term hematopoietic stem cell(LT-HSC),short-term hematopoietic stem cell(ST-HSC),and multipotent progenitor cell in mutant mice was analyzed by flow cytometry.Results:Kmt2c+/-mice model was successfully constructed,and the mRNA expression level of Kmt2c was 28％of that of C57BL/6J mice.The colony formation ability of bone marrow cells of Kmt2c+/-mice in vitro increased with the passage times,and the colony number in the fourth generation was significantly higher than that of control group(P＜0.05).The proportions of LT-HSC and ST-HSC in the primitive hematopoietic cell population of Kmt2c+/-mice was 19.6％±3.3％and 28.9％±4.9％,respectively,which showed an increasing trend compared with 16.9％±2.6％and 18.9％±2.5％in control group,but the difference was not statistically significant(P＞0.05).The white blood cell count of Kmt2c+/-mice gradually increased after 12 weeks of monitoring and reached(9.8±1.0)×109/L at the 14th week,which was significantly higher than(7.3±1.4)× 109/L of control group(P＜0.05).Conclusion:The bone marrow cells of Kmt2c+/-mice have potential of clonal expansion.