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.

Jiuwei Xifeng Granules have become a Chinese patent medicine in the market. Because the formula contains Os Draconis, a top-level protected fossil of ancient organisms, the formula was to be improved by replacing Os Draconis with Ostreae Concha. To evaluate whether the improved formula has the same effectiveness and safety as the original formula, a randomized, double-blind, parallel-controlled, equivalence clinical trial was conducted. This study enrolled 288 tic disorder(TD) of children and assigned them into two groups in 1∶1. The treatment group and control group took the modified formula and original formula, respectively. The treatment lasted for 6 weeks, and follow-up visits were conducted at weeks 2, 4, and 6. The primary efficacy endpoint was the difference in Yale global tic severity scale(YGTSS)-total tic severity(TTS) score from baseline after 6 weeks of treatment. The results showed that after 6 weeks of treatment, the declines in YGTSS-TSS score showed no statistically significant difference between the two groups. The difference in YGTSS-TSS score(treatment group-control group) and the 95%CI of the full analysis set(FAS) were-0.17[-1.42, 1.08] and those of per-protocol set(PPS) were 0.29[-0.97, 1.56], which were within the equivalence boundary [-3, 3]. The equivalence test was therefore concluded. The two groups showed no significant differences in the secondary efficacy endpoints of effective rate for TD, total score and factor scores of YGTSS, clinical global impressions-severity(CGI-S) score, traditional Chinese medicine(TCM) response rate, or symptom disappearance rate, and thus a complete evidence chain with the primary outcome was formed. A total of 6 adverse reactions were reported, including 4(2.82%) cases in the treatment group and 2(1.41%) cases in the control group, which showed no statistically significant difference between the two groups. No serious suspected unexpected adverse reactions were reported, and no laboratory test results indicated serious clinically significant abnormalities. The results support the replacement of Os Draconis by Ostreae Concha in the original formula, and the efficacy and safety of the modified formula are consistent with those of the original formula.
Adolescent ; Child ; Child, Preschool ; Female ; Humans ; Male ; Double-Blind Method ; Drugs, Chinese Herbal/therapeutic use* ; Tic Disorders/drug therapy* ; Treatment Outcome

OBJECTIVE: To investigate the effect of miR-483-5p on hepatocellular carcinoma (HCC) cells proliferation and stemness, as well as the attenuating effect of Pien Tze Huang (PZH). METHODS: Differentially expressed miRNA between HepG2 cells and hepatic cancer stem-like cells (HCSCs) were identified by a miRNA microarray assay. miR-483-5p mimics were transfected into HepG2 cells to explore the effects of miR-483-5p on cell proliferation and stemness. HepG2 cells and HCSCs were treated with PZH (0, 0.25, 0.50 and 0.75 mg/mL) to explore the effects of PZH on the proliferation and stemness, both in non-induced state and the state induced by miR-483-5p mimics. RESULTS: miR-483-5p was significantly up-regulated in HCSCs and its overexpression increased cell proliferation and stemness in HepG2 cells (P<0.05). PZH not only significantly inhibited proliferation in HepG2 cells, but also significantly suppressed the cell proliferation and self-renewal of HCSCs (P<0.05). The effects of miR-483-5p mimics on proliferation and stemness of HepG2 cells were partially abolished by PZH. CONCLUSIONS miR-483-5p promotes proliferation and enhances stemness of HepG2 cells, which were attenuated by PZH, demonstrating that miR-483-5p is a potential molecular target for the treatment of HCC and provide experimental evidence to support clinical use of PZH for patients with HCC.
Humans ; MicroRNAs/metabolism* ; Cell Proliferation/drug effects* ; Liver Neoplasms/drug therapy* ; Carcinoma, Hepatocellular/drug therapy* ; Hep G2 Cells ; Neoplastic Stem Cells/metabolism* ; Drugs, Chinese Herbal/therapeutic use* ; Gene Expression Regulation, Neoplastic/drug effects*

Cemental tear is a rare and indetectable condition unless obvious clinical signs present with the involvement of surrounding periodontal and periapical tissues. Due to its clinical manifestations similar to common dental issues, such as vertical root fracture, primary endodontic diseases, and periodontal diseases, as well as the low awareness of cemental tear for clinicians, misdiagnosis often occurs. The critical principle for cemental tear treatment is to remove torn fragments, and overlooking fragments leads to futile therapy, which could deteriorate the conditions of the affected teeth. Therefore, accurate diagnosis and subsequent appropriate interventions are vital for managing cemental tear. Novel diagnostic tools, including cone-beam computed tomography (CBCT), microscopes, and enamel matrix derivatives, have improved early detection and management, enhancing tooth retention. The implementation of standardized diagnostic criteria and treatment protocols, combined with improved clinical awareness among dental professionals, serves to mitigate risks of diagnostic errors and suboptimal therapeutic interventions. This expert consensus reviewed the epidemiology, pathogenesis, potential predisposing factors, clinical manifestations, diagnosis, differential diagnosis, treatment, and prognosis of cemental tear, aiming to provide a clinical guideline and facilitate clinicians to have a better understanding of cemental tear.
Humans ; Dental Cementum/injuries* ; Consensus ; Diagnosis, Differential ; Cone-Beam Computed Tomography ; Tooth Fractures/therapy*

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 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 design an experimental device for simulating the interface micro motion of bone trabecular prosthesis and carry out the finite element analysis.Methods The experimental device was composed of a screw-in cylinder with threads,a flexible hinge,a micro-motion rod,a trabecular prosthesis,a connecting rod and a fixation post.A model of the experimental device was constructed with SolidWorks software,and then imported into ABAQUS software to establish a finite element model.An axial displacement load was applied to the femur to analyze the effects of the position of the flexible hinge,the gap between the prosthesis and the femur and the length of the connecting rod on the micro motion.Results The interface micro motion produced by the experimental device increased with the distance of the flexible hinge from the lower end of the screwed-in cylinder;the gap between the prosthesis and the femur did not affect the interface micro motion when the gap was not lower than 20 μm;the interface micro motion rose with the length of the connecting rod.Conclusion The experimental device can accurately simulate the micro motion of different bone trabecular prosthesis interfaces,and can be used for studying the effect of the interface micro motion on osseointegration.[Chinese Medical Equipment Journal,2024,45(1):25-30]

This study design of specific identification primers for the ITS2 sequence of F. ussuriensis. The reaction system and conditions were optimized, and PCR-nucleic acid test strips were constructed to realize the visual detection of F. ussuriensis Bark. Through molecular cloning and sequencing technology, we constructed a positive control for F. ussuriensis DNA and formulated quality standards. The established method was evaluated for sensitivity, specificity and reproducibility, and the authenticity of the commercially available samples was identified. Results demonstrated that based on the ITS2 sequences, F. ussuriensis and its mixed forgeries could be distinguished. The PCR products of the authentic F. ussuriensis on test strips showed two bands in the T and C lines, while the pseudo products and negative control showed only one band in the C line, which was consistent with the results of agarose gel electrophoresis. The specificity was 100%, and the sensitivity of the PCR-nucleic acid test strip was up to 0.1 ng·μL^-1, which was 10 times higher than that of the gel electrophoresis assay. 11 out of 16 commercially available samples of F. ussuriensis were qualified, and 5 were unqualified. Collectively, the PCR-nucleic acid test strip method established in this study is specific, rapid, accurate and visualized, which can provide a new technical idea for the detection of F. ussuriensis.

Intramedullary needle(IMN)has the advantages of high healing rate and low incidence of complications in treatment of tibial fracture,and has become one of the most commonly used fixation methods for the treatment of tibial fracture.However,due to the patient's own factors,fracture location and fracture type,infection and surgical treatment,bone nonunion after IMN still occurs in clinic.Bone nonunion leads to the increase of medical cost and prolonged the hospitalization time of patients,which causes great pain to patients,and also brings great challenges to the treatment of orthopedic surgeons.Therefore,this paper reviews the influencing factors of bone nonunion after IMN for tibial fracture,in order to provide reference for clinical treatment.

The purpose of this study was to investigate the regulatory effects of biofilm associated non-coding small RNA(sRNA)00085 on the survival and environmental fitness of Listeria monocytogenes.Homologous recombination technology was used to construct a deletion mutant strain(△sRNA 00085)and a complementary strain(C △sRNA 00085)of the sRNA00085 target gene.The differences in biological characteristics were compared among the standard strain,△sRNA 00085,and C△sRNA 00085.The deletion of sRNA00085 led to a significant decrease in biofilm formation capacity and sensitivity to several antibiotics,including penicillin,piperacillin,doxycycline,tetracycline,vancomycin,and cotrimoxazole.However,only the minimum inhibitory concentration(MIC)of tetracycline exhibited a significant decrease in △sRNA00085.Meanwhile,the decreased biofilm formation and antibiotic resistance of the sRNA00085 mutant were restored in the C△sRNA00085 strain.Furthermore,we investigated the transcription levels of tetracycline resistance-related genes in L.monocytogenes.Down-regu-lated transcription of the tetS gene but no significant difference in transcription of the tetA gene were observed in △sRNA 00085 compared with the standard strain and C△sRNA00085.Moreover,the elimination of sRNA00085 did not affect bacterial growth ability or sensitivity to disinfectants.These findings highlight that sRNA00085 plays an important role in the environ-mental adaptability of L.monocytogenes by affecting bacterial biofilm formation and resistance.