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.

ObjectiveTo investigate the trend and influencing factors of newly reported human immunodeficiency virus (HIV) positivity rate among men who had sex with men (MSM) in Shanghai from 2021 to 2024, and to provide evidence for formulating scientific prevention and control measures of AIDS. MethodsMultiple rounds of cross-sectional questionnaire surveys were conducted among MSM by Shanghai Qing’ai Health Promotion Center. Pearson and Cochran-Armitage trend χ² tests were used to analyze the differences and changes in population characteristics and newly reported HIV positivity rates. A logistic regression model was applied for multivariate analyses of factors associated with newly reported HIV positivity. ResultsA total of 1 653 MSM who had not been previously diagnosed with HIV infection were surveyed. The newly reported HIV positivity rates in 2021, 2023, and 2024 were 7.87%, 3.91%, and 3.06%, respectively, showing a decreasing trend (χ²_trend=13.460, P_trend<0.001). Multivariate analyses revealed that MSM aged 18‒<25 years, residing locally for <1 year, identifying as bisexual, lacking HIV knowledge, and having ≥10 same-sex partners in the past 6 months exhibited higher newly reported HIV positivity rates. Conversely, MSM knowledgeable about HIV prevention, residing locally for 1‒5 years, and engaging in oral sex with male partners in the past 6 months demonstrated lower HIV positivity rates. Annual analyses revealed that MSM with HIV knowledge had lower newly reported HIV positivity rates in 2023 and 2024 (aOR=0.300, 95%CI: 0.811‒0.111; aOR=0.202, 95%CI: 0.085‒0.483). ConclusionThe newly reported HIV positivity rate among MSM in Shanghai from 2021 to 2024 showed a decline. Future interventions should focus on young and mobile MSM, strengthen HIV knowledge education through platforms such as the internet, promote safe sexual behaviors and regular testing, and further expand the coverage of pre-exposure prophylaxis (PrEP) and post-exposure prophylaxis (PEP) to control HIV transmission within this population.

Objective:To investigate long-term auditory changes and characteristics of Alport syndrome（AS） patients with different degrees of renal injury. Methods:Retrospectively analyzing clinical data of patients diagnosed AS from January 2007 to September 2022, including renal pathology, genetic detection and hearing examination. A long-term follow-up focusing on hearing and renal function was conducted. Results:This study included 70 AS patients, of which 33（25 males, 8 females, aged 3.4-27.8 years） were followed up, resulting in a loss rate of 52.9%.The follow-up period ranged from 1.1to 15.8 years, with 16 patients followed-up for over 10 years. During the follow-up, 10 patients presenting with hearing abnormalities at the time of diagnosis of AS had progressive hearing loss, and 3 patients with new hearing abnormalities were followed up, which appeared at 5-6 years of disease course. All of which were sensorineural deafness. While only 3 patients with hearing abnormalities among 13 patients received hearing aid intervention. Of these patients,7 developed end-stage renal disease（ESRD）, predominantly males （6/7）. The rate of long-term hearing loss was significantly different between ESRD group and non-ESRD group（P=0.013）. There was no correlation between the progression of renal disease and long-term hearing level（P>0.05）. kidney biopsies from 28 patients revealed varying degrees of podocyte lesion and uneven thickness of basement membrane. The severity of podocyte lesion was correlated with the rate of long-term hearing loss（P=0.048）, and there was no correlation with the severity of hearing loss（P>0.05）. Among 11 cases, theCOL4A5mutationwas most common （8 out of 11）, but there was no significant correlation between the mutation type and hearing phenotype（P>0.05）. Conclusion:AS patients exhibit progressive hearing loss with significant heterogeneity over the long-term.. THearing loss is more likely to occur 5-6 years into the disease course. Hearing abnormalities are closely related to renal disease status, kidney tissue pathology, and gene mutations, emphasizing the need for vigilant long-term hearing follow-up and early intervention.
Male ; Child ; Female ; Humans ; Nephritis, Hereditary/pathology* ; Retrospective Studies ; Kidney ; Deafness ; Hearing Loss/genetics* ; Kidney Failure, Chronic/pathology* ; Mutation

Tuberculosis （TB） and human immunodeficiency virus infection / acquired immune deficiency syndrome （HIV/AIDS） are both serious global public health threats. Early detection of infected persons and/or patients through TB/HIV bi-directional screening is crucial for prevention and control strategy in China and globally. In recent years， with the promotion and application of new TB and HIV detection technologies worldwide， TB/HIV bi-directional screening technologies and strategies have made remarkable changes. This expert consensus introduces the significance and challenges of TB/HIV bi-directional screening， summarizes important progress of research and applications， and makes recommendations on screening measures and procedures to further strengthen TB/HIV bi-directional screening in China.

ObjectiveTo understand the characteristics of PM_2.5 pollution in the air of Pearl River Delta city in Guangdong Province under the COVID-19 epidemic and the health risks of inhaling elements in PM_2.5. MethodsIn 2022， 10 PM_2.5 monitoring points were set up in 10 districts in Guangzhou， Shenzhen， Foshan and Zhuhai， and air samples were collected for 7 consecutive days every month to analyze the concentration of PM_2.5 and the 12 elements in PM_2.5. The classic "four-step" method was used to evaluate the carcinogenic risk and chronic non-carcinogenic risk of the elements in air PM_2.5 on health. The age-sensitive characteristics of metal elements were combined in the carcinogenic risk assessment， and age-sensitive factors were introduced to analyze the impact of air pollution on population health. ResultsA total of818 samples were collected. and the average annual PM_2.5 concentration in the four cities of the Pearl River Delta was 30.17 （1.00-166.00， s=21.06） μg·m^-3， which was lower than the concentration limit of the secondary standard of the Ambient Air Quality Standard （GB 3095-2012）. The difference of PM_2.5 concentration in the four cities was statistically significant. The PM_2.5 concentrations in Zhuhai and Shenzhen， which were located near the sea， were lower than those in Guangzhou and Foshan. The monthly mean concentration of PM_2.5 in the four cities was the lowest at 13.70 （4.00-34.00， s=5.93） μg·m^-3 in July and the highest at 57.73 （14.00-146.00， s=27.96） μg·m^-3 in January， showing a low concentration from May to October and a high concentration from November to April of the following year. The average daily PM_2.5 concentration exceeded the secondary standard for 29 days， mainly distributed in January and November. The average annual mass concentration of elements in PM_2.5 in the four cities was Al>Mn>Pb>As>Ni>Cr>Se>Sb>Cd>Tl>Be>Hg. AS and Mn have chronic non-carcinogenic risk in population， while Cr， AS， Cd， Be and Ni have carcinogenic risk in population. ConclusionThe PM_2.5 pollution levels of the four cities in the Pearl River Delta are low and variable. Coastal cities are lower than non-coastal cities， which shows the characteristics of first decreasing and then increasing throughout the year. The order of mass concentration of metal elements of PM_2.5 in four cities is basically the same except Be and Ni. As and Mn in PM_2.5 show a certain degree of chronic non-carcinogenic risk， and As， Cr， Cd， Ni and Be have a certain degree of carcinogenic risk. The four cities need to take effective intervention measures to continue to strengthen the pollution control and health protection of Cr， As， Cd and Mn in the air， and control the health burden caused by air pollution.

The advantages of fluorescence detection of uric acid were introduced compared to the traditional detection methods.The preparation process,detection principle and performance of organic,inorganic and organic-inorganic hybrid fluorescent probes were reviewed.The advantages and disadvantages of kinds of fluorescent probes were analyzed when used for uric acid detection,and the futural directions were pointed out for related research.[Chinese Medical Equipment Journal,2024,45(6):93-104]

Objective:To explore the use of near-infrared autofluorescence probe (NIRAF-P) and its application in identifying parathyroid glands during surgery.Methods:A total of 68 patients undergoing thyroid surgery at Peking Union Medical College Hospital and Beijing Longfu Hospital between Dec. 2023 and Jun. 2024 were selected. During the operation, the near-infrared parathyroid gland detector was used to identify the parathyroid gland tissue to be tested, and histopathological examination was performed. The positive predictive value and accuracy of the near-infrared parathyroid gland detector were analyzed.Results:A total of 111 parathyroid glands were identified in 68 patients, and the positive predictive value and accuracy of the NIRAF-P were 95.5% and 94.6%, respectively.Conclusions:The NIRAF-P has high accuracy in identifying parathyroid glands. The standardized application of the NIRAF-P can help improve the efficiency of identifying parathyroid glands during surgery.

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.

AIM To establish a UPLC-MS/MS method for the simultaneous content determination of gallic acid,protocatechuic acid,neomangiferin,catechin,caffeic acid,mangiferin,isomangiferin,albiflorin,paeoniflorin,vitexin,liquiritin,scutellarin,baicalin,liquiritigenin,timosaponin BⅡ,quercetin,wogonoside,benzoylpaeoniflorin,isoliquiritigenin,honokiol,magnolol,norarecaidine,arecaidine,arecoline,epicatechin,baicalein,glycyrrhizinate and wogonin in Dayuan Drink.METHODS The analysis was performed on a 35℃thermostatic Syncronis C18 column(100 mm×2.1 mm,1.7 μm),with the mobile phase comprising of 0.1%formic acid-acetonitrile flowing at 0.3 mL/min in a gradient elution manner,and electron spray inoization source was adopted in positive and negative ion scanning with select reaction monitoring mode.RESULTS Twenty-eight constituents showed good linear relationships within their own ranges(R2≥0.991 0),whose average recoveries were 95.60%-103.53%with the RSDs of 0.60%-5.45%.CONCLUSION This rapid,simple,selective,accurate and reliable method can be used for the quality control of Dayuan Drink.

Objective:To explore the genotypes and frequency distribution of thalassemia in Lingui District,Guilin City,and provide reference for the prevention and control of thalassemia in this area. Methods:The results of genetic testing for thalassemia in 1501 suspected cases at the Second Affiliated Hospital of Guilin Medical University were analyzed retrospectively. The deletional mutations of α-thalassemia were detected by gap-PCR,the non-deletional mutations of α-thalassemia and β-thalassemia mutations were detected by PCR-reverse dot blot (PCR-RDB). Results:In 1501 samples,a total of 678 cases of thalassemia carriers were detected,with a detection rate of 45.17％. Among them,379 cases were α-thalassemia (including deletional α-thalassemia and non-deletional α-thalassemia),with a detection rate of 25.25％,the most common genotype was--SEA/αα (227 cases,15.12％),followed by-α3.7/αα (53 cases,3.53％). 270 cases of β-thalassemia were detected,with a detction rate of 17.99％,and βCD41-42/βN (144 cases,9.59％) was the main genotypes,followed by βCD17/βN (66 cases,4.40％) . In addition,there were 29 cases of αβ compound thalassemia,accounting for 1.93％,and the most common genotype was--SEA/αα complex βCD41-42/βN (5 cases,0.33％). Conclusion:Lingui District in Guilin City is a high-incidence area of thalassemia,and the genotypes of carriers are complex and diverse,with genetic heterogeneity. The results of this study provide a scientific basis for genetic counseling and prenatal diagnosis in this area.