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.

In recent years,the isolation rate of carbapenem-resistant Klebsiella pneunoniae(CRKP)in China has increased year by year.Due to its multidrug resistance and high mortality in patients,CRKP brings severe challen-ges to the clinical treatment.The major mechanism of drug resistance in CRKP is the production of carbapenemases,with Ambler A,B,and D being the common types while Ambler type C comparativly rare.Klebsiella pneumoniae carbapenemase(KPC)is the most common carbapenemase,which belongs to type A.KPC-producing Klebsiella pneumoniae(KPC-KP)widely spreads in the world,with very limited number of effective clinical drugs.In this re-view,advances in the treatment KPC-KP were summarized to provide reference for clinical treatment.

OBJECTIVE To investigate the transcriptomal charactersistics of the striatum in the chronic social defeat stress(CSDS)model mice by using spatial transcriptome analysis and to address the underlying mechanism of the striatum in regulating depressive states.METHODS The CSDS para-digm was employed to establish a depression-like mouse model.The depressive indicators of behavioral despair,anhedonia,and social disorders were assessed through a battery of tests,including the tail suspension test,forced swim test,sucrose preference test,and social interaction experiments.The control mice and the mice exhibiting CSDS-sensitive depression-like behaviors were selected for spatial tran-scriptome sequencing of the striatal region.This sequencing aimed to identify highly expressed genes,followed by KEGG and GO enrichment analyses using the DAVID database.RESULTS The CSDS mouse model effectively induced behavioral despair,anhedonia and social avoidance(P<0.05,P<0.01).Spatial transcriptome analysis revealed 193 differentially expressed genes in the striatum of normal mice.KEGG and GO analyses indicated that these genes were primarily associated with striatal devel-opment,locomotor behaviors,and drug addiction.They were strongly implicated in signaling pathways such as cyclic adenosine monophosphate,cyclic guanosine monophosphate-protein kinase G,calcium signaling,Ras-related protein 1,and mitogen-activated protein kinase,and synaptic linked to GABAergic and dopaminergic neurons.In contrast,CSDS modeling mice led to the identification of 298 differentially expressed genes in the striatum compared with the normal control mice.These genes were significantly enriched in pathways related to neurodegenerative diseases,including Huntington disease,Alzheimer disease,and Parkinson disease.CONCLUSION Depressive states induced by CSDS are associated with the pathological processes underlying neurodegenerative diseases in the striatum.

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 impacts of fatty acid binding protein 4(FABP4)silencing on endoplasmic reticulum stress(ERS)and insulin resistance(IR)in gestational diabetes mellitus(GDM)rats by regulating protein kinase R-like endoplasmic reticulum kinase(PERK)/eukaryotic initiation factor 2α(eIF2α)/transcription factor 4(ATF4)/C/EBP homologous protein(CHOP)signaling pathway.Methods:GDM rat model was established by intraperitoneal injection of streptozotocin(STZ).Rats were injected with FABP4 siRNA plasmid(si-FABP4),negative control plasmid(NC)and PERK activator(CCT020312)via tail vein,and were randomly grouped into Normal group,GDM group,GDM+NC group,GDM+si-FABP4 group and GDM+si-FABP4+CCT020312 group.The levels of FABP4,blood lipids,inflammatory markers and oxidative stress markers in pancreatic tissue were detected,the expres-sions of PERK/eIF2α/ATF4/CHOP signaling pathway-related proteins in pancreatic tissue were detected.HTR-8/SVneo cells were divided into 5 groups:Control group,high glucose(HG)group,HG+NC group,HG+si-FABP4 group,HG+si-FABP4+CCT020312 group.After 24 h,the expressions of FABP4 and PERK/eIF2α/ATF4/CHOP signaling pathway related proteins were detected.Results:Compared with Normal group,the level of FABP4 in the serum and pancreatic tissue of the GDM group were obviously up-regu-lated(P<0.05).FABP4 silencing obviously reduced FBG and IR,decreased the levels of blood lipids,CRP,TNF-α,IL-6 and MDA,and increased the levels of SOD and CAT(P<0.05).Furthermore,FABP4 silencing attenuated pancreatic and placental tissue damages.After CCT020312 up-regulated the phosphorylation levels of PERK and eIF2α and the protein expressions of ATF4 and CHOP,the inhibitory effects of FABP4 silencing on IR,inflammation,oxidative stress,and pancreatic and placental damages in GDM rats were reversed(P<0.05).FABP4 was up-regulated in HTR-8/SVneo cells induced by HG,and silencing FABP4 inhibited the protein ex-pression of the PERK/eIF2α/ATF4/CHOP pathway,while CCT020312 reversed this change(P<0.05).Conclusion:FABP4 silencing improves IR and ERS in GDM rats by inhibiting inflammation and oxidative stress,and the mechanism is related to the inhibition of PERK/eIF2α/ATF4/CHOP signaling pathway.

Purpose: The risk stratification of pediatric anaplastic large cell lymphoma (ALCL) has not been standardized. In this study, new risk factors were included to establish a new risk stratification system for ALCL, and its feasibility in clinical practice was explored. Materials and Methods: On the basis of the non-Hodgkin’s lymphoma Berlin–Frankfurt–Munster 95 (NHL-BFM-95) protocol, patients with minimal disseminated disease (MDD), high-risk tumor site (multiple bone, skin, liver, and lung involvement), and small cell/lymphohistiocytic (SC/LH) pathological subtype were enrolled in risk stratification. Patients were treated with a modified NHL-BFM-95 protocol combined with an anaplastic lymphoma kinase inhibitor or vinblastine (VBL). Results: A total of 136 patients were enrolled in this study. The median age was 8.8 years. The 3-year event-free survival (EFS) and overall survival of the entire cohort were 77.7% (95% confidence interval [CI], 69.0% to 83.9%) and 92.3% (95% CI, 86.1% to 95.8%), respectively. The 3-year EFS rates of low-risk group (R1), intermediate-risk group (R2), and high-risk group (R3) patients were 100%, 89.5% (95% CI, 76.5% to 95.5%), and 67.9% (95% CI, 55.4% to 77.6%), respectively. The prognosis of patients with MDD (+), stage IV cancer, SC/LH lymphoma, and high-risk sites was poor, and the 3-year EFS rates were 45.3% (95% CI, 68.6% to 19.0%), 65.7% (95% CI, 47.6% to 78.9%), 55.7% (95% CI, 26.2% to 77.5%), and 70.7% (95% CI, 48.6% to 84.6%), respectively. At the end of follow-up, one of the five patients who received maintenance therapy with VBL relapsed, and seven patients receiving anaplastic lymphoma kinase inhibitor maintenance therapy did not experience relapse. Conclusion This study has confirmed the poor prognostic of MDD (+), high-risk site and SC/LH, but patients with SC/LH lymphoma and MDD (+) at diagnosis still need to receive better treatment (ClinicalTrials.gov number, NCT03971305).

Background/Aims: Low educational attainment is a well-established risk factor for nonalcoholic fatty liver disease (NAFLD) in developed areas. However, the association between educational attainment and the risk of NAFLD is less clear in China. Methods: A cross-sectional study including over 200,000 Chinese adults across mainland China was conducted. Information on education level and lifestyle factors were obtained through standard questionnaires, while NAFLD and advanced fibrosis were diagnosed using validated formulas. Outcomes included the risk of NAFLD in the general population and high probability of fibrosis among patients with NAFLD. Logistic regression analysis was employed to estimate the risk of NAFLD and fibrosis across education levels. A causal mediation model was used to explore the potential mediators. Results: Comparing with those receiving primary school education, the multi-adjusted odds ratios (95% confidence intervals) for NAFLD were 1.28 (1.16 to 1.41) for men and 0.94 (0.89 to 0.99) for women with college education after accounting for body mass index. When considering waist circumference, the odds ratios (95% CIs) were 0.94 (0.86 to 1.04) for men and 0.88 (0.80 to 0.97) for women, respectively. The proportions mediated by general and central obesity were 51.00% and 68.04% for men, while for women the proportions were 48.58% and 32.58%, respectively. Furthermore, NAFLD patients with lower educational attainment showed an incremental increased risk of advanced fibrosis in both genders. Conclusions In China, a low education level was associated with a higher risk of prevalent NAFLD in women, as well as high probability of fibrosis in both genders.

Xanthoceras sorbifolium seeds have a wide range of applications in the food and pharmaceutical industries. To compare and analyze the chemical compositions of different parts of X. sorbifolium seeds and explore the potential value and research prospects of non-medicinal parts, this study used ultra-high-performance liquid chromatography quadrupole Orbitrap high-resolution mass spectrometry(UHPLC-Q-Orbitrap HRMS) to detect the chemical composition of various parts of the seeds. A total of 82 components were preliminary identified from X. sorbifolium seeds, including 5 amino acids, 4 polyphenols, 3 phenylpropionic acids, 7 organic acids, 15 flavonoids, 6 glycosides, and 23 saponins. Mass spectrometry molecular networking(MN) analysis was conducted on the results from different parts of the seeds, revealing significant differences in the components of the seed kernel, seed coat, and seed shell. The saponins and flavonoids in the seed kernel were superior in terms of variety and content to those in the seed coat and shell. Based on the chromatographic peaks of different parts from multiple batches of samples, multivariate statistical analysis was carried out. Four differential components were determined using HPLC, and the average content of these components in the seed kernel, seed coat, and seed shell were as follows: 0.183 6, 0.887 4, and 1.440 1 mg·g~(-1) for fraxin; 0.035 8, 0.124 1, and 0.044 5 mg·g~(-1) for catechin; 0.032 9, 0.072 0, and 0.221 5 mg·g~(-1) for fraxetin; 0.435 9, 2.114 7, and 0.259 7 mg·g~(-1) for epicatechin. The results showed that catechin and fraxetin had relatively low content in all parts, while fraxin had higher content in the seed coat and seed shell, and epicatechin had higher content in the seed kernel and seed coat. Therefore, the seed coat and seed shell possess certain development value. This study provides rapid analysis and comparison of the chemical compositions of different parts of X. sorbifolium seeds, which offers an experimental basis for the research and clinical application of medicinal substances in X. sorbifolium seeds.
Chromatography, High Pressure Liquid/methods* ; Catechin/analysis* ; Flavonoids/analysis* ; Seeds/chemistry* ; Saponins/analysis*

Polymyxin antibiotics,particularly polymyxin B and polymyxin E(colistin),are often considered a last line of defense against penicillin carbapenem-resistant Enterobacteriaceae(CRE),because of their favorable clinical antibacterial effects.However,the emergence and spread of plasmid-mediated colistin resistance genes(mcr),and their multiple isoforms,have posed a substantial threat to public health in recent years.The mcr-1 genes exhibit complexity in both host and transmis-sion routes,and diversity in both the genetic environment and ecological locus distribution.Herein,we discuss the prevalence,transmission routes,drug resistance and transmission mechanisms of mcr-1 positive isolates,on the basis of epidemiological studies of Enterobacteriaceae carrying mcr-1 worldwide.to provide a theoretical reference for researchers.