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 explore incidence trend of hepatitis C in Chifeng City, Inner Mongolia Autonomous Region from 2008 to 2022, so as to provide the basis for formulating prevention and control measures for hepatitis C. Methods: Data of reported hepatitis C cases in Chifeng City from 2008 to 2022 was collected through the Infectious Disease Information Reporting Management System. Trends in incidence of hepatitis C were analyzed using annual percent change (APC) and average annual percent change (AAPC). Impact of age, period and birth cohort on the risk of developing hepatitis C were analyzed by an age-period-cohort model. Results: The annual average reported incidence rate of hepatitis C in Chifeng City was 59.13/105 from 2008 to 2022. The incidence showed an upward trend from 2008 to 2018 (APC=9.405%, P<0.05) and a downward trend from 2018 to 2022 (APC=-17.475%, P<0.05), but the overall trend was not statistically significant (AAPC=0.937%, P>0.05). The age-period-cohort model analysis showed that the incidence risks of hepatitis C in the residents aged 0 to 4 years and 45 to 84 years were higher than those in the residents aged 40 to 44 years (the control group). The incidence risk of hepatitis C increased with age from 40 to 79 years. Compared with 2008-2012, the incidence risk of hepatitis C showed an increasing trend followed by a decline in 2008-2022. The incidence risk was higher in 2013-2017 and lower in 2018-2022 than in 2008-2012. The incidence risk of hepatitis C showed an increasing trend followed by a decreasing trend by using the birth cohort from 1968 to 1972 as the control. The birth cohort from 1953 to 1977 had a higher incidence risk of hepatitis C than other birth cohorts. Conclusions The overall incidence of hepatitis C in Chifeng City from 2008 to 2022 appeared a tendency towards a decline, and the incidence risk increased with age. Screening and health education for the elderly and high-risk birth cohorts should be strengthened.

Objective To investigate the impact of emodin(EM)on vascular endothelial cell injury in rats with diabetes macroangiopathy by regulating hypoxia inducible factor-1α(HIF-1α)/vascular endothelial growth factor(VEGF)signaling pathway.Methods SD rats were divided into blank group and modeling group,the rats in the modeling group were fed with high fat and high sugar combined with N-nitro-L-arginine methyl ester to build the diabetes macroangiopathy model,and the blank group was fed with ordinary diet.The vascular endothelial cells successfully isolated from the thoracic aorta of rats in blank group and modeling group were named control group and model group,respectively.The vascular endothelial cells in the modeling group were divided into model group,dimethyloxallyl glycine(DMOG)group(10 μmol·L-1DMOG),combined group(80 mg·L-1EM+10 μmol·L-1 DMOG)and experimental-L,-M,-H groups(20,40,80 mg·L-1 EM).The apoptosis of rat vascular endothelial cells was detected by flow cytometry;Western blot was applied to detect the expression of HIF-1αand VEGF proteins in rat vascular endothelial cells.Results The apoptosis rates of vascular endothelial cells in experimental-M,-H groups,DMOG group,combined group,model group and control group were(10.18±0.36)％,(6.28±0.20)％,(24.96±1.18)％,(12.36±0.49)％,(18.76±0.68)％and(4.59±0.26)％;HIF-1α protein levels were 0.96±0.07,0.78±0.06,2.03±0.12,1.05±0.13,1.58±0.12 and 0.69±0.05;VEGF protein levels were 0.59±0.05,0.23±0.02,0.98±0.06,0.63±0.04,0.86±0.07 and 0.11±0.01.The above indexes in the model group were compared with the control,DMOG,experimental-M and experimental-H groups,and the above indexes in the combined group were compared with the experimental-H group,and the differences were statistically significant(all P＜0.05).Conclusion EM may inhibit HIF-1α/VEGF pathway to improve vascular endothelial cell injury in rats with diabetes macroangiopathy.

Digital intraoral scanning is a hot topic in the field of oral digital technology.In recent years,digital intra-oral scanning has gradually become the mainstream technology in orthodontics,prosthodontics,and implant dentistry.The precision of digital intraoral scanning and the accuracy and stitching of data collection are the keys to the success of the impression.However,the operators are less familiar with the intraoral scanning characteristics,imaging process-ing,operator scanning method,oral tissue specificity of the scanned object,and restoration design.Thus far,no unified standard and consensus on digital intraoral scanning technology has been achieved at home or abroad.To deal with the problems encountered in oral scanning and improve the quality of digital scanning,we collected common expert opin-ions and sought to expound the causes of scanning errors and countermeasures by summarizing the existing evidence.We also describe the scanning strategies under different oral impression requirements.The expert consensus is that due to various factors affecting the accuracy of digital intraoral scanning and the reproducibility of scanned images,adopting the correct scanning trajectory can shorten clinical operation time and improve scanning accuracy.The scanning trajec-tories mainly include the E-shaped,segmented,and S-shaped methods.When performing fixed denture restoration,it is recommended to first scan the abutment and adjacent teeth.When performing fixed denture restoration,it is recommend-ed to scan the abutment and adjacent teeth first.Then the cavity in the abutment area is excavated.Lastly,the cavity gap was scanned after completing the abutment preparation.This method not only meets clinical needs but also achieves the most reliable accuracy.When performing full denture restoration in edentulous jaws,setting markers on the mucosal tissue at the bottom of the alveolar ridge,simultaneously capturing images of the vestibular area,using different types of scanning paths such as Z-shaped,S-shaped,buccal-palatal and palatal-buccal pathways,segmented scanning of dental arches,and other strategies can reduce scanning errors and improve image stitching and overlap.For implant restora-tion,when a single crown restoration is supported by implants and a small span upper structure restoration,it is recom-mended to first pre-scan the required dental arch.Then the cavity in the abutment area is excavated.Lastly,scanning the cavity gap after installing the implant scanning rod.When repairing a bone level implant crown,an improved indi-rect scanning method can be used.The scanning process includes three steps:First,the temporary restoration,adjacent teeth,and gingival tissue in the mouth are scanned;second,the entire dental arch is scanned after installing a standard scanning rod on the implant;and third,the temporary restoration outside the mouth is scanned to obtain the three-di-mensional shape of the gingival contour of the implant neck,thereby increasing the stability of soft tissue scanning around the implant and improving scanning restoration.For dental implant fixed bridge repair with missing teeth,the mobility of the mucosa increases the difficulty of scanning,making it difficult for scanners to distinguish scanning rods of the same shape and size,which can easily cause image stacking errors.Higher accuracy of digital implant impres-sions can be achieved by changing the geometric shape of the scanning rods to change the optical curvature radius.The consensus confirms that as the range of scanned dental arches and the number of data concatenations increases,the scanning accuracy decreases accordingly,especially when performing full mouth implant restoration impressions.The difficulty of image stitching processing can easily be increased by the presence of unstable and uneven mucosal mor-phology inside the mouth and the lack of relatively obvious and fixed reference objects,which results in insufficient ac-curacy.When designing restorations of this type,it is advisable to carefully choose digital intraoral scanning methods to obtain model data.It is not recommended to use digital impressions when there are more than five missing teeth.

Objective:To further improve the understanding of paroxysmal nocturnal hemoglobinuria (PNH), we retrospectively analyzed and summarized the clinical characteristics, treatment status, and survival status of patients with PNH in Zhejiang Province.Methods:This study included 289 patients with PNH who visited 20 hospitals in Zhejiang Province. Their clinical characteristics, comorbidity, laboratory test results, and medications were analyzed and summarized.Results:Among the 289 patients with PNH, 148 males and 141 females, with a median onset age of 45 (16-87) years and a peak onset age of 20-49 years (57.8% ). The median lactic dehydrogenase (LDH) level was 1 142 (604-1 925) U/L. Classified by type, 70.9% (166/234) were classical, 24.4% (57/234) were PNH/bone marrow failure (BMF), and 4.7% (11/234) were subclinical. The main clinical manifestations included fatigue or weakness (80.8%, 235/289), dizziness (73.4%, 212/289), darkened urine color (66.2%, 179/272), and jaundice (46.2%, 126/270). Common comorbidities were hemoglobinuria (58.7% ), renal dysfunction (17.6% ), and thrombosis (15.0% ). Moreover, 82.3% of the patients received glucocorticoid therapy, 70.9% required blood transfusion, 30.7% used immunosuppressive agents, 13.8% received anticoagulant therapy, and 6.3% received allogeneic hematopoietic stem cell transplantation. The 10-year overall survival (OS) rate was 84.4% (95% CI 78.0% -91.3% ) . Conclusion:Patients with PNH are more common in young and middle-aged people, with a similar incidence rate between men and women. Common clinical manifestations include fatigue, hemoglobinuria, jaundice, renal dysfunction, and recurrent thrombosis. The 10-year OS of this group is similar to reports from other centers in China.

Amino acid surfactants (AAS) have excellent properties such as low toxicity,antibacterial,mildness,and corrosion resistance. In recent years,they have been widely applied in the field of daily chemicals,food and pharmaceutical industry. It is pointed out that the structure at molecular level largely affects the physical and chemical properties of AAS materials. In this work,the structures of solid-state N-lauroyl-L-alanine (NLLA) including intermolecular interactions,molecular local dynamics and molecular assembly were investigated by a variety of solid-state nuclear magnetic resonance (SSNMR) techniques. Based on 2D 1H-1H double quantum-single quantum (2D 1H-1H DQ-SQ),1H-1H DQ sideband pattern and molecular simulation,it was found that there was a stable intermolecular hydrogen bond formed between the carboxyl units of two NLLA molecules. Combined with the study of 2D frequency switched Lee—Goldberg heteronuclear correlation (2D 13C-1H FSLG-HETCOR) and 13C T1,another type of hydrogen bond was probed,which existed between amide units of neighboring molecules. In addition,the conformation of alkyl chain ends was investigated. According to 1D 13C{1H}cross polarization/magic angle spinning (CP/MAS) and 2D 13C-1H FSLG-HETCOR spectra,it was revealed that the alkyl-chain ends had both gauche and trans conformations. Moreover,the trans conformation showed two distinct 13C chemical shifts,originated from two NLLA molecular assembly forms. Accordingly,two NLLA molecular assembly structures were suggested which were transoid form and cisoid form. This work provided a SSNMR investigation strategy for characterizing the molecular local structure and dynamics of AAS materials,which helped task of researching and developing materials with improved chemical and physical properties.

Objective:To explore the best practices for the management of hospital medical consumables quantity-based procurement under the policy of quantity-based procurement for orthopedic medical consumables,and to promote the implementation of quantity-based procurement of orthopedic medical consumables.Methods:The relevant policies on quantity-based procurement of orthopedic medical consumables in recent years in China were sorted out,and the characteristics and management requirements of the policies were analyzed.The difficulties encountered by medical institutions in the practical process of quantity-based procurement of medical consumables in terms of procurement model,usage supervision and supply chain management were analyzed.A multi-departmental management collaboration model was established based on the two-tier management structure consisting of orthopedic clinical expert teams and quantity-based procurement medical consumable management teams of Peking Union Medical College Hospital,and a dynamic monitoring platform for medical consumables procurement data was built using information technology.The implementation of quantity-based procurement of orthopedic medical consumables for knee and hip joints in the implementation cycle of orthopedic medical consumables procurement based on the two-tier management structure of the hospital from 2022 to 2023 was evaluated.Results:In the execution cycle of quantity-based procurement based on the two-tier management structure,the completion of the quantity-based procurement medical consumables agreement could be monitored in real time.The agreement volume statistics time had been shortened from the original one week to real-time statistics,saving 83.6%of the medical consumables cost throughout the year.Conclusion:The quantity-based procurement management model for orthopedic medical consumables based on a two-tier management structure can strengthen the information monitoring means of medical consumables,improve the completion rate of quantity-based procurement agreements for orthopedic medical consumables,and promote the smooth and orderly implementation of quantity-based procurement of orthopedic medical consumables by building a dynamic monitoring platform for quantity-based procurement data for medical consumables.

Objective: To identify the maximum tolerated dose (MTD) of docetaxel combined with a fixed dose of cisplatin (75 mg/m 2 ) delivered as hyperthermic intraperitoneal chemotherapy (HIPEC) in patients with ovarian cancer. Methods: In this phase I trial, a time-to-event Bayesian optimal interval design was used.Docetaxel was given at a starting dose of 60 mg/m2 and was increased in 5 mg/m2 increments until the MTD was determined or the maximum dose level of 75 mg/m2 was reached. The doselimiting toxicity (DLT) rate was set at 25%, with a total sample size of 30 patients. HIPEC was delivered immediately following debulking surgery at a target temperature of 43°C for 90 minutes. Results: From August 2022 to November 2022, 30 patients were enrolled. Among the patients who received a dose of docetaxel ≤65 mg/m2 , no DLT was reported. DLTs were observed in one patient who received 70 mg/m2 docetaxel (grade 3 anaemia) and in three patients who received 75 mg/m2 docetaxel (one case of grade 3 anaemia, one case of grade 3 hepatic impairment and one case of grade 4 thrombocytopenia). Patients treated with docetaxel 75 mg/m2 in combination with cisplatin 75 mg/m2 had an estimated DLT rate of 25%, which was the closest to the target DLT rate and was therefore chosen as the MTD. Conclusion Docetaxel, in combination with a fixed dose of cisplatin (75 mg/m2), can be used safely at intraperitoneal doses of 75 mg/m2 in ovarian cancer patients who received HIPEC (43°C, 90 minutes) following debulking surgery.

Objective: To identify the maximum tolerated dose (MTD) of docetaxel combined with a fixed dose of cisplatin (75 mg/m 2 ) delivered as hyperthermic intraperitoneal chemotherapy (HIPEC) in patients with ovarian cancer. Methods: In this phase I trial, a time-to-event Bayesian optimal interval design was used.Docetaxel was given at a starting dose of 60 mg/m2 and was increased in 5 mg/m2 increments until the MTD was determined or the maximum dose level of 75 mg/m2 was reached. The doselimiting toxicity (DLT) rate was set at 25%, with a total sample size of 30 patients. HIPEC was delivered immediately following debulking surgery at a target temperature of 43°C for 90 minutes. Results: From August 2022 to November 2022, 30 patients were enrolled. Among the patients who received a dose of docetaxel ≤65 mg/m2 , no DLT was reported. DLTs were observed in one patient who received 70 mg/m2 docetaxel (grade 3 anaemia) and in three patients who received 75 mg/m2 docetaxel (one case of grade 3 anaemia, one case of grade 3 hepatic impairment and one case of grade 4 thrombocytopenia). Patients treated with docetaxel 75 mg/m2 in combination with cisplatin 75 mg/m2 had an estimated DLT rate of 25%, which was the closest to the target DLT rate and was therefore chosen as the MTD. Conclusion Docetaxel, in combination with a fixed dose of cisplatin (75 mg/m2), can be used safely at intraperitoneal doses of 75 mg/m2 in ovarian cancer patients who received HIPEC (43°C, 90 minutes) following debulking surgery.

Objective: To identify the maximum tolerated dose (MTD) of docetaxel combined with a fixed dose of cisplatin (75 mg/m 2 ) delivered as hyperthermic intraperitoneal chemotherapy (HIPEC) in patients with ovarian cancer. Methods: In this phase I trial, a time-to-event Bayesian optimal interval design was used.Docetaxel was given at a starting dose of 60 mg/m2 and was increased in 5 mg/m2 increments until the MTD was determined or the maximum dose level of 75 mg/m2 was reached. The doselimiting toxicity (DLT) rate was set at 25%, with a total sample size of 30 patients. HIPEC was delivered immediately following debulking surgery at a target temperature of 43°C for 90 minutes. Results: From August 2022 to November 2022, 30 patients were enrolled. Among the patients who received a dose of docetaxel ≤65 mg/m2 , no DLT was reported. DLTs were observed in one patient who received 70 mg/m2 docetaxel (grade 3 anaemia) and in three patients who received 75 mg/m2 docetaxel (one case of grade 3 anaemia, one case of grade 3 hepatic impairment and one case of grade 4 thrombocytopenia). Patients treated with docetaxel 75 mg/m2 in combination with cisplatin 75 mg/m2 had an estimated DLT rate of 25%, which was the closest to the target DLT rate and was therefore chosen as the MTD. Conclusion Docetaxel, in combination with a fixed dose of cisplatin (75 mg/m2), can be used safely at intraperitoneal doses of 75 mg/m2 in ovarian cancer patients who received HIPEC (43°C, 90 minutes) following debulking surgery.