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.

Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by progressive cognitive decline, functional impairment, and neuropsychiatric symptoms. It represents the most prevalent form of dementia among the elderly population. Accumulating evidence indicates that oxidative stress plays a pivotal role in the pathogenesis of AD. Notably, elevated levels of oxidative stress have been observed in the brains of AD patients, where excessive reactive oxygen species (ROS) can cause extensive damage to lipids, proteins, and DNA, ultimately compromising neuronal structure and function. Amyloid β‑protein (Aβ) has been shown to induce mitochondrial dysfunction and calcium overload, thereby promoting the generation of ROS. This, in turn, exacerbates Aβ aggregation and enhances tau phosphorylation, leading to the formation of two pathological features of AD: extracellular Aβ plaque deposition and intracellular neurofibrillary tangles (NFTs). These events ultimately culminate in neuronal death, forming a vicious cycle. The interplay between oxidative stress and these pathological processes constitutes a core link in the pathogenesis of AD. The signaling pathways mediating oxidative stress in AD include Nrf2, RCAN1, PP2A, CREB, Notch1, NF‑κB, ApoE, and ferroptosis. Nrf2 signaling pathway serves as a key regulator of cellular redox homeostasis, exerts important antioxidant capacity and protective effects in AD. RCAN1 signaling pathway, as a calcineurin inhibitor, and modulates AD progression through multiple mechanisms. PP2A signaling pathway is involved in regulating tau phosphorylation and neuroinflammation processes. CREB signaling pathway contributes to neuroplasticity and memory formation; activation of CREB improves cognitive function and reduce oxidative stress. Notch1 signaling pathway regulates neuronal development and memory, participates in modulation of Aβ production, and interacts with Nrf2 toco-regulate antioxidant activity. NF‑κB signaling pathway governs immune and inflammatory responses; sustained activation of this pathway forms “inflammatory memory”, thereby exacerbating AD pathology. ApoE signaling pathway is associated with lipid metabolism; among its isoforms, ApoE-ε4 significantly increases the risk of AD, leading to elevated oxidative stress, abnormal lipid metabolism, and neuroinflammation. The ferroptosis signaling pathway is driven by iron-dependent lipid peroxidation, and the subsequent release of lipid peroxidation products and ROS exacerbate oxidative stress and neuronal damage. These interconnected pathways form a complex regulatory network that regulates the progression of AD through oxidative stress and related pathological cascades. In terms of therapeutic strategies targeting oxidative stress, among the drugs currently used in clinical practice for AD treatment, memantine and donepezil demonstrate significant therapeutic efficacy and can improve the level of oxidative stress in AD patients. Some compounds with antioxidant effects (such asα-lipoic acid and melatonin) have shown certain potential in AD treatment research and can be used as dietary supplements to ameliorate AD symptoms. In addition, non-drug interventions such as calorie restriction and exercise have been proven to exerted neuroprotective effects and have a positive effect on the treatment of AD. By comprehensively utilizing the therapeutic characteristics of different signaling pathways, it is expected that more comprehensive multi-target combination therapy regimens and combined nanomolecular delivery systems will be developed in the future to bypass the blood-brain barrier, providing more effective therapeutic strategies for AD.

Objective To investigate the feasibility and clinical experience of kidney transplantation from donors with Marfan syndrome (MFS). Methods Clinical data of 2 recipients undergoing kidney transplantation from the same MFS patient were retrospectively analyzed and literature review of 2 cases was conducted. Characteristics and clinical diagnosis and treatment of kidney transplantation from MFS patients were summarized. Results The Remuzzi scores of the left and right donor kidneys of the MFS patient during time-zero biopsy were 1 and 2. No significant difference was observed in the renal arteriole wall compared with other donors of brain death and cardiac death. Two recipients who received kidney transplantation from the MFS patient suffered from postoperative delayed graft function. After short-term hemodialysis, the graft function of the recipients received the left and right kidney began to gradually recover at postoperative 10 d and 20 d. After discharge, serum creatinine level of the recipient received the left kidney was ranged from 80 to 90 μmol/L, whereas that of the recipient received the right kidney kept declining, and the lowest serum creatinine level was 232 μmol/L before the submission date (at postoperative 43 d). Through literature review, two cases successfully undergoing kidney transplantation from the same MFS donor were reported. Both two recipients experienced delayed graft function, and then renal function was restored to normal. Until the publication date, 1 recipient has survived for 6 years, and the other recipient died of de novo cerebrovascular disease at postoperative 2 years. Conclusions MFS patients may serve as an acceptable source of kidney donors. However, the willingness and general conditions of the recipients should be carefully evaluated before kidney transplantation. Intraoperatively, potential risk of tear of renal arterial media should be properly treated. Extensive attention should be paid to the incidence of postoperative complications.

Objective To investigate the clinical characteristics,treatment methods,and prognosis of a-cute leukemia patients with extramedullary infiltration.Methods The clinical characteristics and treatment methods of 47 acute leukemia patients with extramedullary infiltration admitted to the Affiliated Hospital of Guizhou Medical University from April 2014 to April 2023 were retrospectively analyzed.Subgroup analysis was performed according to whether there was extramedullary infiltration before transplantation,and whether there was isolated extramedullary recurrence after transplantation.Based on this analysis,the patients were di-vided into the pre-transplantation radiotherapy group and pre-transplantation non-radiotherapy group,the post-transplantation radiotherapy group and post-transplantation non-radiotherapy group.According to the treatment methods of central nervous system leukemia(CNSL),the patients were divided into the intrathecal injection group(n=12)and combination of intrathecal injection and radiotherapy group(n=13).The local remission situation,survival duration,and toxic and side effects of radiotherapy and chemotherapy were com-pared.Results For acute leukemia patients with extramedullary infiltration,the overall survival time(OS)in the radiotherapy group was better than that in the non-radiotherapy group(median OS:706 d vs.151 d,P=0.015).Subgroup analysis showed that the OS of the pre-transplantation radiotherapy group was better than that of the pre-transplantation non-radiotherapy group(median OS:592 d vs.386 d,P=0.035).For CNSL,the combination of intrathecal injection and radiotherapy group had a better OS than the intrathecal injection group(median OS:547 d vs.388 d,P=0.045).The event-free survival time(EFS)of the radiotherapy group was better than that of the non-radiotherapy group(median EFS:175 d vs.50 d,P=0.005).The COX pro-portional-hazards model showed that treatment with or without radiotherapy had a significant impact on the OS of acute leukemia patients with extramedullary infiltration.The risk of death in the pre-transplantation non-radiotherapy group was 2.231 times higher than that in the pre-transplantation radiotherapy group(HR=3.231,95％CI:1.021-10.227,P=0.046).Compared with the non-radiotherapy group,the radiother-apy group had a higher local remission and a lower risk of haematological toxicity,infection,and haemorrhage.Conclusion Radiotherapy can rapidly alleviate the local symptoms of acute leukemia complicated with extr-amedullary infiltration,prolong the survival time of these patients,and reduce the risk of hematologic toxicity,infection,and haemorrhage.

Amantadine(AMD)residue can accumulate in organisms through the food chain and cause serious harm to human body.AMD can specifically bind to AMD specific aptamer and cause its conformation to change from a random single strand to a stem-loop structure.To avoid the influence of excess nucleotides on binding of aptamer to AMD,the truncation of the AMD original aptamer J was optimized by retaining an appropriate stem-loop structure,and a new type of truncation aptamers was developed in this work.By comparing the truncated aptamer with the original aptamer,it was found that the truncated aptamer J-7 had better affinity and specificity with AMD.The detection limit of AMD was 0.11 ng/mL by using J-7 as specific recognition element and molybdenum disulfide nanosheet(MoS2Ns)as signal amplification element.The developed method base on truncated aptamer J-7 was used for detection of AMD in milk,yogurt and SD rat serum samples for the first time with recoveries of 86.6%-108.2%.This study provided a reference for truncating other long sequence aptamers and provided a more sensitive detection method for monitoring AMD residues in food.

This article discussed the evolution of the traditional preparation process of Pinelliae Rhizoma Fermentata.The production methods for Pinelliae Rhizoma Fermentata in Song Dynasty include cake-making of Pinelliae Rhizoma together with ginger juice and fermentation after cake-making,and the former method of cake-making was the mainstream.The process technology in Jin and Yuan Dynasties inherited from that in Song Dynasty,and the application of Pinelliae Rhizoma Fermentata had certain limitations.The medical practitioners of Ming Dynasty elucidated the mechanism of processing of Pinelliae Rhizoma Fermentata,and proposed the view of"sliced Pinelliae Rhizoma being potent while fermented Pinelliae Rhizoma being mild".In the Ming Dynasty,LI Shi-Zhen defined the cake-making process and fermentation process for Pinelliae Rhizoma,and HAN Mao's Han Shi Yi Tong(Han's Clear View of Medicine)contained five prescriptions for the processing of Pinelliae Rhizoma Fermentata,which had the epoch-making signficance in the expansion of prescriptions for the processing of Pinelliae Rhizoma Fermentata.In the Qing Dynasty,HAN Fei-Xia's ten methods for making Pinelliae Rhizoma Fermentata were summarized on the basis of the methods recorded in Han Shi Yi Tong,and at that time,the processing of Pinelliae Rhizoma Fermentata and the preparation of Massa Medicata Fermentata interacted with each other.After the founding of the People's Republic of China,the local experience in the preparation of Pinelliae Rhizoma Fermentata was deeply influenced by the methods in the Qing Dynasty,and the local preparation technical standards gradually became the same.Moreover,this article also explored the issues of the importance of"Pinelliae Rhizoma"and"ingredients for fermentation",the pre-treatment of Pinelliae Rhizoma,the distinction between cake-making process and fermentation process for Pinelliae Rhizoma,the amount of flour added as well as the timing of adding,the addition of Massa Medicata Fermentata powder,the role of Alum in Pinelliae Rhizoma Fermentata and so on.

ObjectiveProtein arginine methyltransferases (PRMTs) play pivotal roles in numerous cellular biological processes. However, the precise regulatory effects of PRMTs on the fate determination of mesenchymal stromal/stem cells (MSCs) remain elusive. Our previous studies have shed light on the regulatory role and molecular mechanism of PRMT5 in MSC osteogenic differentiation. This study aims to clarify the role and corresponding regulatory mechanism of PRMT7 during the adipogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs). Methods(1) Human bone marrow-derived mesenchymal stem cells (hBMSCs) were cultured in a medium that induces adipogenesis. We used qRT-PCR and Western blot to monitor changes in PRMT7 expression during adipogenic differentiation. (2) We created a cell line with PRMT7 knocked down and assessed changes in PRMT7 expression and adipogenic capacity using Oil Red O staining, qRT-PCR and Western blot. (3) We implanted hBMSCs cell lines mixed with a collagen membrane subcutaneously into nude mice and performed Oil Red O staining to observe ectopic lipogenesis in vivo. (4) A cell line overexpressing PRMT7 was generated, and we examined changes in PRMT7 expression using qRT-PCR and Western blot. We also performed Oil Red O staining and quantitative analysis after inducing the cells in lipogenic medium. Additionally, we assessed changes in PPARγ expression. (5) We investigated changes in insulin-like growth factor 1 (IGF-1) expression in both PRMT7 knockdown and overexpressing cell lines using qRT-PCR and Western blot, to understand PRMT7’s regulatory effect on IGF-1 expression. siIGF-1 was transfected into the PRMT7 knockdown cell line to inhibit IGF-1 expression, and knockdown efficiency was confirmed. Then, we induced cells from the control and knockdown groups transfected with siIGF-1 in lipogenic medium and performed Oil Red O staining and quantitative analysis. Finally, we assessed PPARγ expression to explore IGF-1’s involvement in PRMT7’s regulation of adipogenic differentiation in hBMSCs. Results(1) During the adipogenesis process of hBMSCs, the expression level of PRMT7 was significantly reduced (P<0.01). (2) The adipogenic differentiation ability of PRMT7 knockdown group was significantly stronger than that of control group (P<0.001). (3) The ectopic adipogenic differentiation ability of PRMT7 knockdown group was significantly stronger than that of control group. (4) The adipogenic differentiation ability of the PRMT7 overexpression group was significantly weaker than that of the control group (P<0.01). (5) The expression level of IGF-1 increased after PRMT7 knockdown (P<0.000 1). The expression level of IGF-1 decreased after PRMT7 overexpression (P<0.000 1), indicating that PRMT7 regulates the expression of IGF-1. After siIGF-1 transfection, the expression level of IGF-1 in all cell lines decreased significantly (P<0.001). The ability of adipogenic differentiation of knockdown group transfected with siIGF-1 was significantly reduced (P<0.01), indicating that IGF-1 affects the regulation of PRMT7 on adipogenic differentiation of hBMSCs. ConclusionIn this investigation, our findings elucidate the inhibitory role of PRMT7 in the adipogenic differentiation of hBMSCs, as demonstrated through both in vitro cell-level experiments and in vivo subcutaneous transplantation experiments conducted in nude mice. Mechanistic exploration revealed that PRMT7’s regulatory effect on the adipogenic differentiation of hBMSCs operates via modulation of IGF-1 signaling pathway. These collective findings underscore PRMT7 as a potential therapeutic target for fatty metabolic disorders, thereby offering a novel avenue for leveraging PRMT7 and hBMSCs in the therapeutic landscape of relevant diseases.

Objective:Utilizing a seven-year panel data set of a targeted admission medical student cohort,this study aims to examine their career development and provide insights for retaining healthcare talent in township health centers and village clinics in the central and western rural areas of China.Method:Starting from 2015,cohorts of targeted and general clinical graduates from four medical colleges in central and western China were selected and tracked for their career progression.Results:The targeted graduates'standardized residency training and medical licensing examination pass rates were similar to those of general clinical graduates.They advanced more quickly in professional titles and positions,with 82.5%becoming attending physicians and 16.2%obtaining positions in the seventh year after graduation.However,their monthly income was significantly lower than that of general clinical graduates,and this income discrepancy expanded annually.As of December 2022,among the 493 targeted graduates who completed their contracts,38.5%stayed in grassroots positions.Of those who left,60%moved to county-level or higher public hospitals,7.9%pursued further studies,and 27.7%were unemployed.Conclusion:Targeted graduates are well-trained and advance rapidly in their careers,but their lower income significantly impacts their willingness to remain at the grassroots level.After completing their service period,about one-third of the targeted graduates choose to stay in grassroots positions.

A 6-month primary care quality improvement (QI) project was conducted for 63 general practice residents at Union Hospital Affiliated to Tongji Medical College of Huazhong University of Science and Technology from November 2021 to April 2022. The effectiveness of the QI project on the post competency of general practice residents was comprehensively assessed by three dimensions: self-satisfaction, objective evaluation and teacher-evaluation. The overall satisfaction score of general practice residents was significantly increased after the implementation of QI project((3.83±0.67) vs. (3.41±0.63), t=3.35, P=0.009). The total score of objective assessment was increased from (73.48±8.04) before the project implementation to (78.14±5.24) after the implementation ( t=3.37, P=0.001). The total score of training effectiveness significantly increased from (57.57±11.84) before the project implementation to (79.27±8.40) after the implementation ( t=30.07, P<0.001). The results indicate that the primary care QI project can improve the post competency of general practice residents, and also improve the self-satisfaction of residents for active learning and participation in the training.

The breakage pattern of unit particles during the production of oral solid dosage forms (OSD) is closely related to the quality of intermediate or final products. To accurately characterize the particles and study the evolution law of particle breakage, the Bonding model of the discrete element method (DEM) was used to investigate the breakage patterns of model parameters, particle shape and process conditions (loading mode and loading rate) on the dynamic breakage, force-time curve, breakage rate, maximum breakage size ratio and fracture strength of particles. The results showed that the particle breakage force was positively correlated with normal strength and bonded disk scale, negatively correlated with normal stiffness per unit area and tangential stiffness per unit area, and weakly correlated with tangential strength. The particle breakage rate was negatively correlated with the aspect ratio of the particles, and the maximum breakage size ratio was positively correlated with the aspect ratio of the particles; among the three loading modes, the breakage rate of compression breakage model was the largest, the breakage rate of shear breakage model was the second largest, and the breakage rate of wear breakage model was the smallest; the maximum breakage size ratio was positively correlated with the loading rate, the loading mode and the loading rate had no mutual influence on particle breakage rate, but had mutual influence on the maximum breakage size ratio. The research results will provide a theoretical basis for the shift of OSD from batch manufacturing to advanced manufacturing.