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 observe the effect of Banxia Xiexintang （BXT） on the proliferation of human gastric cancer HGC-27， MKN-45， and AGS cells and its mechanism. MethodCell counting kit-8 （CCK-8） was used to detect the effects of different concentrations of BXT-containing serum （5%， 10%， and 20%） on the proliferation of HGC-27， MKN-45， and AGS cells. A mitochondrial membrane potential probe （TMRE） was used to detect the expression of mitochondrial membrane potential in cells. A kit was used to detect iron ion （Fe²⁺） content， lipid peroxide （LPO）， and superoxide dismutase （SOD） activity. Western blot was used to detect the protein expression levels of glycogen synthase3β （GSK3β）， phosphorylated GSK3β （p-GSK3β）， nuclear factor E₂ related factor 2 （Nrf2）， and glutathione peroxidase 4 （GPX4）. The real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） was used to detect the mRNA expression of member 11 of the cystine/glutamic acid reverse transporter solute vector family 7 （SLC7A11）， member 2 of the heavy chain solute vector family 3 （SLC3A2）， transferrin receptor 3 （TFRC）， and tumor protein （TP）53. ResultCCK-8 results showed that BXT and capecitabine could significantly reduce the survival rate of three kinds of gastric cancer cells after treatment with drug-containing serum for 24 h （P<0.01）. After 48 h of intervention with drug-containing serum， the survival rate of three kinds of gastric cancer cells was significantly decreased in both the capecitabine group and the BXT group compared with the blank group. The BXT group was dose-dependent， with 20% BXT having the most significant effect （P<0.01）. In terms of biochemical indicators of ferroptosis， compared with the blank group， BXT and capecitabine significantly decreased the expression of mitochondrial membrane potential （P<0.01） and SOD activity （P<0.01） and significantly increased the contents of LPO and Fe²⁺ （P<0.01）， so as to improve the sensitivity of gastric cancer cells to ferroptosis. In terms of the Nrf2/GPX4 pathway， compared with the blank group， the BXT group could reduce the protein expressions of p-GSK3β， Nrf2， and GPX4 （P<0.01） in gastric cancer cells and increase mRNA expressions of SLC7A11 and SLC3A2 （P<0.05）. It could also increase the protein expression of GSK3β （P<0.01） and mRNA expression of TP53 and TFRC （P<0.05， P<0.01） in gastric cancer cells. Inhibition of the Nrf2/GPX4 pathway induces ferroptosis in gastric cancer cells. Compared with the capecitabine group， the 20% BXT group showed a more obvious effect. ConclusionBanxia Xiexintang can induce ferroptosis in gastric cancer cells HGC-27， MKN-45， and AGS by inhibiting the Nrf2/GPX4 pathway.

The Ehlers-Danlos syndrome(EDS)is a rare inherent connective tissue disorder.The prev-alence of EDS in the population is estimated at one out of ten thousand to one out of a hundred thousand.The vascular EDS(vEDS)are rare among the subtypes but are the worst in prognosis.The article reports a case of vEDS admitted to the hospital.The patient was a young man complaining of a sudden onset of aphasia in right hemiparalysis and severe left abdominal pain for unknown reasons.The diagnosis was made after the genetic testing.The patient suffered from vEDS.Then,the multi-disciplinary team(MDT)made a treatment plan tailored to this young patient.The complexity in classification and delusive presentations of the EDS make the correct diagnosis very challenging.This article hopes to report this case and to share the experiences to the bet-ter understanding of this disease.

Background::Bladder cancer, characterized by a high potential of tumor recurrence, has high lifelong monitoring and treatment costs. To date, tumor cells with intrinsic softness have been identified to function as cancer stem cells in several cancer types. Nonetheless, the existence of soft tumor cells in bladder tumors remains elusive. Thus, our study aimed to develop a microbarrier microfluidic chip to efficiently isolate deformable tumor cells from distinct types of bladder cancer cells.Methods::The stiffness of bladder cancer cells was determined by atomic force microscopy (AFM). The modified microfluidic chip was utilized to separate soft cells, and the 3D Matrigel culture system was to maintain the softness of tumor cells. Expression patterns of integrin β8 (ITGB8), protein kinase B (AKT), and mammalian target of rapamycin (mTOR) were determined by Western blotting. Double immunostaining was conducted to examine the interaction between F-actin and tripartite motif containing 59 (TRIM59). The stem-cell-like characteristics of soft cells were explored by colony formation assay and in vivo studies upon xenografted tumor models. Results::Using our newly designed microfluidic approach, we identified a small fraction of soft tumor cells in bladder cancer cells. More importantly, the existence of soft tumor cells was confirmed in clinical human bladder cancer specimens, in which the number of soft tumor cells was associated with tumor relapse. Furthermore, we demonstrated that the biomechanical stimuli arising from 3D Matrigel activated the F-actin/ITGB8/TRIM59/AKT/mTOR/glycolysis pathways to enhance the softness and tumorigenic capacity of tumor cells. Simultaneously, we detected a remarkable up-regulation in ITGB8, TRIM59, and phospho-AKT in clinical bladder recurrent tumors compared with their non-recurrent counterparts.Conclusions::The ITGB8/TRIM59/AKT/mTOR/glycolysis axis plays a crucial role in modulating tumor softness and stemness. Meanwhile, the soft tumor cells become more sensitive to chemotherapy after stiffening, that offers new insights for hampering tumor progression and recurrence.

Objective:To assess the applicability of fully automatic pipeline automated testing for internal quality control (automated quality control).Methods:Stability, assay efficiency and implementation costs of 18 biochemical tests, 5 immunoturbidimetric tests and 11 chemical illuminescent tests in the Department of Laboratory Medicine of Peking Union Hospital from January 2019 to July 2022 were evaluated using automated quality control implementation methods. The detailed method is as follows: quality control materials for biochemical, immunoturbidimetric and chemiluminescent tests were stored in the refrigerator in the pipeline which was controlled by the intermediate software, and were automatically retrieved and tested as pre-set followed by documenting and storing. The quality control setup for the biochemical tests included refreshing quality control materials daily and weekly,both of which were paralleled for 3 months. The on-line storage stability of quality control materials in the pipeline was evaluated by comparing the coefficients of variation ( CV) of the quality control results between the two patterns. Effect of automated quality control application was evaluated using 6 indicators, including the results′ variation of automatically performed and manually performed quality controls, the out-of-controlled rate, the consumption of quality control materials, the change of staff workload, the impact on the testing time of the first sample, and the failure rate of automated quality control. Results:(1) Storage stability of quality control materials in the pipeline: under the pattern of weekly refresh of the biochemical quality control materials, except for total carbon dioxide (TCO 2) (the CVs of low and high level quality control were respectively 20.24% and 21.82%) and sodium (the CV of low level quality control was 1.51%) that were greater than the allowable variation set by the laboratory, the CVs of the rest tests meet the lab requirements on the allowable variations. (2) The results′ variation of quality control in automatically performed and manually performed control patterns: in the patterns of daily refresh of biochemical quality control materials and weekly refresh of immunoturbidimetric and chemiluminescent quality control materials, the CVs of both low and high levels of quality control were lower in the automatically performed control pattern than that in manually performed pattern for 8 chemiluminescent items of dehydroepiandrosterone sulfate, estradiol, follicle stimulating hormone, luteinizing hormone, serum ferritin, serum folic acid, vitamin B12 and testosterone, 3 immunologic items of complement 3, C reactive protein and immunoglobulin G, and 10 biochemical items of alkaline phosphatase, glucose, calcium, chloride, potassium, lactate dehydrogenase, sodium, urea, low density lipoprotein cholesterol, and adenosine deaminase. The out-of-control rates of biochemistry, immunoturbidimetric and chemiluminescence tests in both quality control patterns conformed with the clinical routine work requirements. (3) Comparison of quality control materials′ consumption: compared with manually performed quality control, weekly consumption of automatically performed chemiluminescent quality control materials decreased 37.5% (from 8 ml to 5 ml); weekly consumption of automatically performed immunoturbidimetric quality control materials decreased 33.3% (from 3 ml to 2 ml). (4)Comparison of staff workload and first sample testing time: compared with manually performed quality control, automatical quality control reduced manual work by about 156 steps per week, and the daily initial testing time was earlier by 15 min on average. The failure rate was 54.5% (37/64) during the early-stage application of the automated quality control which dropped to 10.2% (13/128) in the late-stage. Conclusion:The results of automated quality control detected in the pipeline system meet the quality indicators′ requirements of the laboratory, and the application of automated quality control can improve the quality control, save costs, reduce workload, and improve work efficiency.

Clinical application of mass spectrometry technology has attracted the attention of clinical laboratory experts due to its high sensitivity, high specificity, and capacities of simultaneous detection of multiple compounds. In recent years, mass spectrometry technology has made significant achievements in the fields of identification of pathogenic microorganism, detection of trace elements and heavy metals, small molecule hormones, vitamins, amino acids, peptides and proteins, as well as therapeutic drug monitoring (TDM) and poisoning drugs screening. In order to further clarify the opportunities and challenges brought by this complex mass spectrometry technology in the field of clinical laboratory, the Chinese Journal of Laboratory Medicine invited experts and scholars of laboratory medicine to share their experience and opinions on related items focusing on the positioning of mass spectrometry technology in the clinical laboratory, the development and improvement of the clinical laboratory by mass spectrometry technology, the challenges of interpreting mass spectrometry test results, the challenges of operating and managing clinical mass spectrometry laboratories, and ways of improving the application of clinical mass spectrometry laboratories with this technology. Agreement was achieved in that the introduction of mass spectrometry technology into the clinical laboratory could bring new directions and opportunities for clinical testing and research, and also is associated with a series of challenges such as the difficulty of sample pretreatment, the high cost and complexity of mass spectrometry technology, the complexity of data processing and interpretation, the lack of standards and norms, and the issue of determining the price of mass spectrometry examinations.

This article mainly elaborated the acupuncture and moxibustion treatment scheme of"eighteen needles for reproduction"based on Professor You Zhaoling's reproductive axis theory of"heart-kidney-Chong Ren-uterus".The"eighteen needles for reproduction"aims to regulate the disordered reproductive axis in gynecological reproductive diseases.It selects the acupoints on the main viscera and meridians of the reproductive axis as the main acupoints,and the acupoints regulating the qi and blood of the related viscera as the matching acupoints.Through specific manipulation,it can regulate the qi and blood,dredge the meridians,and treat the viscera,so as to nourish the essence and help pregnancy,and provide ideas and reference for the treatment of gynecological reproductive diseases with acupuncture and moxibustion.

Objective:To explore the efficiency of a modified caries risk assessment tool(MCAT)on caries-risk prediction of children in Nanning.Methods:MCAT was designed based on caries-risk assessment tool(CAT)of American Academy of Pediatric Dentistry(AAPD)and the caries related factors of the primary school children in Guangxi,China.A cohort study was conducted in 332 children aged 3-year-old in kindergarten of Jiangnan District,Nanning,Guangxi.The data were integrated through questionnaires and oral exam-ination.The MCAT data were respectively scored by CAT and Cariogram and the caries-risk of the children was evaluated.The develop-ment of increased average caires incidece over a period of 1.5 years was compared,the predictive capacity of the methods was com-pared.Results:The ranks of caires risk assessed by CAT and Cariogram were significant different(Z=-10.34,P＜0.001),and the consistency of the 2 methods was poor(Kappa=0.234,P＜0.001).After 1.5 years,there was significant statistical difference of the caries prevalence rate between the low-high and moderate-high risk groups,and dmft increments between the moderate-high risk groups e-valuated by CAT(P＜0.05).There was significant difference of the caries prevalence rate between each risk groups and dmft increments between the low-high and moderate-high risk groups evaluated by Cariogram(P＜0.05).The AUC of CAT and Cariogram was 0.571 and 0.722 respectively(P＜0.001).In the prediction models of caries risk,the fitting of CAT was poor(P＜0.001),while that of Cariogram was better(P=1.00).Cariogram analysis showed that the chance of developing new caries lesions of the subjects with moderate and high caries risk was 2.86 and 11.65 times more than those with low caries risk.Conclusion:MCAT com-bined with Cariogram can more efficiently predict new caries de-velopment in 3-year-old children.

Objective To explore the evidence,urinary biomarkers,and partial mechanisms of hypercoagulability in the pathogenesis of IgA vasculitis(IgAV).Methods Differential expression of proteins in the urine of 10 healthy children and 10 children with IgAV was screened using high-performance liquid chromatography-tandem mass spectrometry,followed by Reactome pathway analysis.Protein-protein interaction(PPI)network analysis was conducted using STRING and Cytoscape software.In the validation cohort,15 healthy children and 25 children with IgAV were included,and the expression levels of differential urinary proteins were verified using enzyme-linked immunosorbent assay.Results A total of 772 differential proteins were identified between the IgAV group and the control group,with 768 upregulated and 4 downregulated.Reactome pathway enrichment results showed that neutrophil degranulation,platelet activation,and hemostasis pathways were involved in the pathogenesis of IgAV.Among the differential proteins,macrophage migration inhibitory factor(MIF)played a significant role in neutrophil degranulation and hemostasis,while thrombin was a key protein in platelet activation and hemostasis pathways.PPI analysis indicated that thrombin directly interacted with several proteins involved in inflammatory responses,and these interactions involved MIF.Validation results showed that compared to healthy children,children with IgAV had significantly higher urine thrombin/creatinine and urine MIF/creatinine levels(P<0.05).Conclusions Thrombin contributes to the pathogenesis of IgAV through interactions with inflammatory factors.Urinary thrombin and MIF can serve as biomarkers reflecting the hypercoagulable and inflammatory states in children with IgAV.

Pulmonary nocardiosis and pneumocystis pneumonia are rare opportunistic infections clinically,both tend to occur in immunocompromised patients.However,the co-infection of the two has been reported rarely.With complex clinical and imaging findings,the co-infection is difficult to diagnose and treat.This article reports the dia-gnosis and treatment process of a case of the co-infection with Nocardia asiatica and Pneumocystis,reviewed the relevant literatures,so as to improve the understanding of the disease.