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 pharmacokinetic characteristics of etoricoxib tablets in healthy Chinese subjects and to evaluate the bioequivalence and safety of the test and reference formulations.Methods In a randomised,single-dose,two-period,two-sequence crossover trial,28 healthy subjects were enrolled under the fasting and fed conditions,respectively,who received a single oral dose of 60 mg of etoricoxib tablets in the test or reference formulation.The concentration of etoricoxib in plasma was detected by LC-MS/MS,and the main pharmacokinetic parameters were calculated to evaluate bioequivalence and using WinNonlin 8.2 software.Results The main pharmacokinetic parameters of the test and reference preparations were as follows:The fasting condition Cmax of etoricoxib were(1 176.96±287.95)and(1 164.93±189.65)ng·mL-1;AUC0-t were(18 651.95±6 100.27)and(19 241.39±6 107.48)ng·h·mL-1;and AUC0-∞ were(19 939.15±7 553.27)and(20 536.31±7 223.40)ng·h·mL-1.The fed condition Cmax of etoricoxib were(913.50±184.72)and(878.59±164.35)ng·mL-1;and AUC0-t were(19 085.22±5 155.01)and(18 669.54±4 508.21)ng·h·mL-1;AUC0-∞ were(20 103.77±5 567.02)and(19 528.05±4 989.74)ng·h·mL-1.The 90％confidence intervals for the geometric mean ratios of the main pharmacokinetic parameters in the fasting and fed conditions fell between 80.00％and 125.00％.The incidence of adverse events in the fasting and fed conditions were 28.57％and 21.43％,respectively.Conclusion Two kinds of etoricoxib tablets are bioequivalent,and have similar safety in healthy Chinese subjects.

Objective:To understand the epidemiological characteristics of human respiratory syncytial virus (HRSV) among acute respiratory infection (ARI) cases in 16 provinces of China from 2009 to 2023.Methods:The data of this study were collected from the ARI surveillance data from 16 provinces in China from 2009 to 2023, with a total of 28 278 ARI cases included in the study. The clinical specimens from ARI cases were screened for HRSV nucleic acid from 2009 to 2023, and differences in virus detection rates among cases of different age groups, regions, and months were analyzed.Results:A total of 28 278 ARI cases were enrolled from January 2009 to September 2023. The age of the cases ranged from<1 month to 112 years, and the age M ( Q1, Q3) was 3 years (1 year, 9 years). Among them, 3 062 cases were positive for HRSV nucleic acid, with a total detection rate of 10.83%. From 2009 to 2019, the detection rate of HRSV was 9.33%, and the virus was mainly prevalent in winter and spring. During the Corona Virus Disease 2019 (COVID-19) pandemic, the detection rate of HRSV fluctuated between 6.32% and 18.67%. There was no traditional winter epidemic peak of HRSV from the end of 2022 to the beginning of 2023, and an anti-seasonal epidemic of HRSV occurred from April to May 2023. About 87.95% (2 693/3 062) of positive cases were children under 5 years old, and the difference in the detection rate of HRSV among different age groups was statistically significant ( P<0.001), showing a decreasing trend of HRSV detection rate with the increase of age ( P<0.001). Among them, the HRSV detection rate (25.69%) was highest in children under 6 months. Compared with 2009-2019, the ranking of HRSV detection rates in different age groups changed from high to low between 2020 and 2023, with the age M (Q1, Q3) of HRSV positive cases increasing from 1 year (6 months, 3 years) to 2 years (11 months, 3 years). Conclusion:Through 15 years of continuous HRSV surveillance analysis, children under 5 years old, especially infants under 6 months old, are the main high-risk population for HRSV infection. During the COVID-19 pandemic, the prevalence and patterns of HRSV in China have changed.

Objective: To establish a novel classification system for predicting the risk of intraoperative neurophysiological monitoring (IONM) events in surgically-treated patients with kyphotic deformity. Methods: Patients with kyphotic deformity who underwent surgical correction of cervicothoracic, thoracic, or thoracolumbar kyphosis in our center from July 2005 to December 2020 were recruited. We proposed a classification system to describe the morphology of the spinal cord on T2-weighted sagittal magnetic resonance imaging: type A, circular/symmetric cord with visible cerebrospinal fluid (CSF) between the cord and vertebral body; type B, circular/oval/symmetric cord with no visible CSF between the cord and vertebral body; type C, spinal cord that is fattened/deformed by the vertebral body, with no visible CSF between the cord and vertebral body. Furthermore, based on type C, the spinal cord compression ratio (CR) < 50% was defined as the subtype C-, while the spinal cord CR ≥ 50% was defined as the subtype C+. IONM event was documented, and a comparative analysis was made to evaluate the prevalence of IONM events among patients with diverse spinal cord types. Results: A total of 294 patients were reviewed, including 73 in type A; 153 in type B; 53 in subtype C- and 15 in subtype C+. Lower extremity transcranial motor-evoked potentials and/or somatosensory evoked potentials were lost intraoperatively in 41 cases (13.9%), among which 4 patients with type C showed no return of spinal cord monitoring data. The 14 subtype C+ patients (93.3%) had IONM events. Univariate logistic regression analysis showed that patients with a type C spinal cord (subtype C-: odds ratio [OR], 10.390; 95% confidence interval [CI], 2.215–48.735; p = 0.003; subtype C+, OR, 497.000; 95% CI, 42.126– 5,863.611; p < 0.001) are at significantly higher risk of a positive IONM event during deformity correction compared to those with a type A. In further multiple logistic regression analysis, the spinal cord classification (OR, 5.371; 95% CI, 2.966–9.727; p < 0.001) was confirmed as an independent risk factor for IONM events. Conclusion We presented a new spinal cord classification system based on the relative position of the spinal cord and vertebrae to predict the risk of IONM events in patients with kyphotic deformity. In patients with type C spinal cord, especially those in C+ cases, it is essential to be aware of potential IONM events, and adopt standard operating procedures to facilitate neurological recovery.

Patients with severe trauma require an extremely timely treatment and transfusion plays an irreplaceable role in the emergency treatment of such patients. An increasing number of evidence-based medicinal evidences and clinical practices suggest that patients with severe traumatic bleeding benefit from early transfusion of low-titer group O whole blood or hemostatic resuscitation with red blood cells, plasma and platelet of a balanced ratio. However, the current domestic mode of blood supply cannot fully meet the requirements of timely and effective blood transfusion for emergency treatment of patients with severe trauma in clinical practice. In order to solve the key problems in blood supply and blood transfusion strategies for emergency treatment of severe trauma, Branch of Clinical Transfusion Medicine of Chinese Medical Association, Group for Trauma Emergency Care and Multiple Injuries of Trauma Branch of Chinese Medical Association, Young Scholar Group of Disaster Medicine Branch of Chinese Medical Association organized domestic experts of blood transfusion medicine and trauma treatment to jointly formulate Chinese expert consensus on blood support mode and blood transfusion strategies for emergency treatment of severe trauma patients ( version 2024). Based on the evidence-based medical evidence and Delphi method of expert consultation and voting, 10 recommendations were put forward from two aspects of blood support mode and transfusion strategies, aiming to provide a reference for transfusion resuscitation in the emergency treatment of severe trauma and further improve the success rate of treatment of patients with severe trauma.

Objective:To investigate the effect of Hounsfield Units (HU) at the upper instrumented vertebra (UIV) on postoperative proximal junctional kyphosis (PJK) after pelvic fixation with second sacral alar-iliac (S 2AI) screws in patients with degenerative spinal deformity. Methods:A total of 66 patients with degenerative spinal deformity who underwent pelvic fixation with S 2AI screws from August 2015 to April 2021 were retrospectively reviewed. The cohort included 4 males and 62 females, aged 61.9±7.3 years (range, 43-78 years), with a follow-up period of 18.4±14.3 months (range, 6-60 months). The prevalence of PJK was 26%. Patients were divided into two groups based on the occurrence of PJK during postoperative follow-up: the PJK group (17 cases) and the non-PJK group (49 cases). HU measurements were taken at the UIV, the vertebral body cephalad to the UIV (UIV+1), and the L 3 and L 4 vertebral bodies. The following sagittal radiographic parameters were measured: thoracic kyphosis (TK), lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT), pelvic incidence (PI), PI minus LL (PI-LL), and sagittal vertical axis (SVA) at preoperative, postoperative, and final follow-up. General information and HU values of the two groups were compared, and Pearson correlation analysis was performed on HU values, bone mineral density (BMD), and T scores. Logistic regression analysis was used to explore the risk factors for PJK. Results:The HU values of L 3 and L 4 were significantly positively correlated with the BMD and T scores respectively ( r=0.530, P<0.001; r=0.537, P<0.001). Age, gender, follow-up time, fixation levels, bone mineral density (BMD) and T-score were not significantly different between PJK and non-PJK group. The average HU values of UIV and UIV+1 in PJK group was 104.3±32.9, whlie the average HU values of UIV and UIV+1 in non-PJK group was 133.7±29.5. The difference of HU between the two groups was statistically significant ( t=3.441, P=0.001). Logistic regression analysis showed that average HU values of UIV and UIV+1 [ OR=0.960, 95% CI(0.933, 0.987), P=0.004] and changes of lumbar lordosis [ OR=1.049, 95% CI(1.007, 1.092), P=0.023] were independent risk factors for PJK, with an optimal cutoff obtained by ROC that 106 for average HU values of UIV and UIV+1 and 22.5° for changes of LL. Conclusion:The average HU values of UIV and UIV+1 < 106 and changes of lumbar lordosis > 22.5° are independent risk factors for PJK after pelvic fixation with second sacralalar-iliac in patients with degenerative spinal deformity.

AIM To establish a two reference substances for determination of multiple components(TRSDMC)method for the simultaneous content determination of neochlorogenic acid,chlorogenic acid,cryptochlorogenic acid,luteolin-7-O-glucuronide,isochlorogenic acid B,isochlorogenic acid A,isochlorogenic acid C,deoxyelephantopin,isodeoxyelephantopin,isoscabertopin and scabertopin in Elephantopus scabre L..METHODS The analysis was performed on a 35℃thermostatic Waters Symmetry C18,Phenomenex C18,Agilent ZORBAX Eclipse Plus C18 columns(4.6 mm×250 mm,5.0 μm),with the mobile phase comprising of acetonitrile and 0.1%phosphoric acid flowing at 1.0 mL/min in a gradient elution manner,and the detection wavelengths were set at 220,326 nm.Chlorogenic acid was used as an internal standard to calculate the relative correction factors of neochlorogenic acid,cryptochlorogenic acid,luteolin-7-O-glucuronide,isochlorogenic acid B,isochlorogenic acid A and isochlorogenic acid C,while isodeoxyelephantopin was used as an internal standard to calculate the relative correction factors of deoxyelephantopin,scabertopin and isoscabertopin,after which the content determination was made.Subsequently,cluster analysis,principal component analysis and orthogonal partial least squares-discriminant analysis were conducted.RESULTS Eleven constituents showed good linear relationships within their own ranges(r≥0.999 0),whose average recoveries were 95.3%-103.4%with the RSDs of 0.32%-3.45%.The result obtained by TRSDMC approximated those obtained by external standard method.Isochlorogenic acid A,isochlorogenic acid C,isochlorogenic acid B,chlorogenic acid,luteolin-7-O-glucuronide and cryptochlorogenic acid were taken as quality differential constituents.CONCLUSION This reliable and stable method can be used for the quality control of E.scabre.

Objective:To understand the epidemiological characteristics of human respiratory syncytial virus (HRSV) among acute respiratory infection (ARI) cases in 16 provinces of China from 2009 to 2023.Methods:The data of this study were collected from the ARI surveillance data from 16 provinces in China from 2009 to 2023, with a total of 28 278 ARI cases included in the study. The clinical specimens from ARI cases were screened for HRSV nucleic acid from 2009 to 2023, and differences in virus detection rates among cases of different age groups, regions, and months were analyzed.Results:A total of 28 278 ARI cases were enrolled from January 2009 to September 2023. The age of the cases ranged from<1 month to 112 years, and the age M ( Q1, Q3) was 3 years (1 year, 9 years). Among them, 3 062 cases were positive for HRSV nucleic acid, with a total detection rate of 10.83%. From 2009 to 2019, the detection rate of HRSV was 9.33%, and the virus was mainly prevalent in winter and spring. During the Corona Virus Disease 2019 (COVID-19) pandemic, the detection rate of HRSV fluctuated between 6.32% and 18.67%. There was no traditional winter epidemic peak of HRSV from the end of 2022 to the beginning of 2023, and an anti-seasonal epidemic of HRSV occurred from April to May 2023. About 87.95% (2 693/3 062) of positive cases were children under 5 years old, and the difference in the detection rate of HRSV among different age groups was statistically significant ( P<0.001), showing a decreasing trend of HRSV detection rate with the increase of age ( P<0.001). Among them, the HRSV detection rate (25.69%) was highest in children under 6 months. Compared with 2009-2019, the ranking of HRSV detection rates in different age groups changed from high to low between 2020 and 2023, with the age M (Q1, Q3) of HRSV positive cases increasing from 1 year (6 months, 3 years) to 2 years (11 months, 3 years). Conclusion:Through 15 years of continuous HRSV surveillance analysis, children under 5 years old, especially infants under 6 months old, are the main high-risk population for HRSV infection. During the COVID-19 pandemic, the prevalence and patterns of HRSV in China have changed.

Objective To investigate the clinical characteristics and prognosis of pneumococcal meningitis(PM),and drug sensitivity of Streptococcus pneumoniae(SP)isolates in Chinese children.Methods A retrospective analysis was conducted on clinical information,laboratory data,and microbiological data of 160 hospitalized children under 15 years old with PM from January 2019 to December 2020 in 33 tertiary hospitals across the country.Results Among the 160 children with PM,there were 103 males and 57 females.The age ranged from 15 days to 15 years,with 109 cases(68.1% )aged 3 months to under 3 years.SP strains were isolated from 95 cases(59.4% )in cerebrospinal fluid cultures and from 57 cases(35.6% )in blood cultures.The positive rates of SP detection by cerebrospinal fluid metagenomic next-generation sequencing and cerebrospinal fluid SP antigen testing were 40% (35/87)and 27% (21/78),respectively.Fifty-five cases(34.4% )had one or more risk factors for purulent meningitis,113 cases(70.6% )had one or more extra-cranial infectious foci,and 18 cases(11.3% )had underlying diseases.The most common clinical symptoms were fever(147 cases,91.9% ),followed by lethargy(98 cases,61.3% )and vomiting(61 cases,38.1% ).Sixty-nine cases(43.1% )experienced intracranial complications during hospitalization,with subdural effusion and/or empyema being the most common complication[43 cases(26.9% )],followed by hydrocephalus in 24 cases(15.0% ),brain abscess in 23 cases(14.4% ),and cerebral hemorrhage in 8 cases(5.0% ).Subdural effusion and/or empyema and hydrocephalus mainly occurred in children under 1 year old,with rates of 91% (39/43)and 83% (20/24),respectively.SP strains exhibited complete sensitivity to vancomycin(100% ,75/75),linezolid(100% ,56/56),and meropenem(100% ,6/6).High sensitivity rates were also observed for levofloxacin(81% ,22/27),moxifloxacin(82% ,14/17),rifampicin(96% ,25/26),and chloramphenicol(91% ,21/23).However,low sensitivity rates were found for penicillin(16% ,11/68)and clindamycin(6% ,1/17),and SP strains were completely resistant to erythromycin(100% ,31/31).The rates of discharge with cure and improvement were 22.5% (36/160)and 66.2% (106/160),respectively,while 18 cases(11.3% )had adverse outcomes.Conclusions Pediatric PM is more common in children aged 3 months to under 3 years.Intracranial complications are more frequently observed in children under 1 year old.Fever is the most common clinical manifestation of PM,and subdural effusion/emphysema and hydrocephalus are the most frequent complications.Non-culture detection methods for cerebrospinal fluid can improve pathogen detection rates.Adverse outcomes can be noted in more than 10% of PM cases.SP strains are high sensitivity to vancomycin,linezolid,meropenem,levofloxacin,moxifloxacin,rifampicin,and chloramphenicol.[Chinese Journal of Contemporary Pediatrics,2024,26(2):131-138]

Objective To investigate the effects of different disinfection methods on ultrasound imaging and application firmness of ultrasound-guided subclavian vein puncture.Methods A total of 138 patients received ultrasound-guided subclavian vein puncture were selected as the study subjects and randomly divided into the chlorhexidine alcohol group,the iodophor group and the chlorhexidine alcohol+ iodophor group,with 46 cases in each group.They were disinfected with chlorhexidine alcohol,iodophor,and chlorhexidine alcohol and iodophor,respectively.The disinfection effect,ultrasound imaging and application fixation of patients in the three groups were compared.Results There was no statistically significant difference in the bacterial count or disinfection qualification rate of the puncture sites before and after disinfection of patients among the three groups(P>0.05).The ultrasound imaging clarity rate during puncture in the chlorhexidine alcohol group was significantly lower than those in the iodophor group and the chlorhexidine alcohol+iodophor group(P<0.05);while the rate of sticking up or shedding of application in the iodophor group 24 hours after puncture was significantly higher than those in the chlorhexidine alcohol group and the chlorhexidine alcohol+iodophor group(P<0.05).Conclusion Disinfecting the puncture area twice with chlorhexidine alcohol and then disinfecting the ultrasound exploration area once with iodophor can obtain satisfactory disinfection effect for patients undergoing ultrasound-guided subclavian vein puncture,with clearer ultrasound imaging and stronger adhesion of the application at the same time.