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 investigate the effects of applying the "4C" teaching method combined with the Gibbs' reflective cycle to clinical nursing teaching in the department of urology.Methods:A total of 68 nursing students who practiced in the urology department of our hospital were divided using a lottery method into experimental group ( n=35, entering the second and third wards for internship) and control group ( n=33, entering the first and fourth wards). The experimental group was taught using the "4C" teaching method combined with the Gibbs' reflective cycle, including four teaching steps (connection, concept, concrete practice, and conclusion) and regular reflective discussions. The control group received traditional teaching, which covered entrance education, centralized theoretical training, skills demonstration, and exit assessment. At the end of internship, the two groups were compared in terms of self-directed learning ability, nursing competency, and theoretical and practical scores. SPSS 23.0 was used to perform the t test. Results:The self-directed learning scores of the experimental group and the control group were (227.37±12.91) and (207.09±16.27), respectively. The nursing competency scores were (156.66±12.49) and (138.06±17.23), respectively. The experimental group was significantly superior to the control group in self-directed learning ability ( t=5.71, P<0.001), nursing competency ( t=5.12, P<0.001), theoretical score ( t=3.03, P=0.004), and practical score ( t=4.88, P<0.001). Conclusions:The "4C" teaching method combined with the Gibbs' reflective cycle can effectively improve nursing students' self-directed learning ability and nursing competency, and help them better master knowledge and skills.

Cancer stem cell(CSC)are the"seed"cells in the occurrence,development,metastasis and recurrence of colorectal cancer.Targeted killing of CSC provides a new target for anti-colorectal cancer therapy.Ferroptosis is an iron-dependent cell death mode due to the abnormal accumulation of intracellular i-ron ions,which results in the massive reactive oxygen species(ROS)and lipid peroxides,leading to cell death.Studies have shown that cancer stem cells are more enriched in iron ions than non-CSC,which provides a new perspective for targeting ferropto-sis in cancer stem cells against colorectal cancer.This article re-views the research progress of inducing CSC ferroptosis in the treatment of colorectal cancer,such as targeted regulation of SLC7A11 expression in CSC,chelating iron in CSC lysosomes,targeting CSC phenotypic plasticity,reversing CSC iron homeo-stasis,and targeting CSC lipid droplet metabolism induce CSC ferroptosis,which provides new ideas for anti-tumor therapy.

This study was aimed at investigating the antimicrobial susceptibility and genomic characteristics of multidrug resistant diarrheagenic Escherichia coli isolated from human and food samples in Henan Province from 2017 to 2022.A total of 101 strains of multidrug resistant diarrheagenic E.coli were subjected to antimicrobial susceptibility testing with the broth di-lution method.Whole genome sequencing was performed to analyze the antimicrobial resistance genes,multilocus sequence typ-ing,and plasmid types.The sequencing data were used to construct a phylogenetic tree based on core genome single-nucleotide polymorphisms(cgSNPs).The isolates showed the highest resistance to ampicillin(87.1％),followed by tetracycline(79.2％)and nalidixic acid(64.4％).The resistance rate to cefotaxime was 38.6％.All 101 strains were classified into 60 STs,among which ST10,ST1491,and ST38 were dominant.Moreover,23 distinct plasmid replicons were identified,among which IncFIB was dominant.Diverse antimicrobial resistance genes(including quinolone,aminoglycoside,β-lactamase,and tetracycline)were identified.Insertion sequences(IS26,IS903B,and ISECP 1)were identified in upstream and downstream analysis of the gene context of the extended-spectrum β-lactamase bla CTX-M-14 and bla CTX-M-55 genes.In conclusion,multidrug resistant diarrhea-genic Escherichia coli isolated from clinical and food samples in Henan Province showed high genetic diversity and high antimi-crobial resistance.The dissemination of blaCTX-M carried by the strains was shown to be associated with the insertion sequence(IS).

Objective:To explore the optimal storage condition and time of umbilical cord blood from collection to preparation.Methods:Collect cord blood samples from 30 healthy newborns,with each new born's umbilical cord blood was divided into two parts on average.One part was stored in cold storage(4 ℃)and the other was stored at room temperature(20-24 ℃).Samples were taken at 24,36,48,60 and 72 h,respectively,total nucleated cells(TNC)count and TNC viability was analyzed.Flow cytometry was used to detect the ratio of viable CD34+cells to viable CD45+cells and viability of CD34+cells,and colony-forming unit-granulocyte-macrophage(CFU-GM)count was performed by hematopoietic progenitor cell colony culture.The change trend of each index over time was observed,and the differences in each index was compared between cold storage and room temperature storage under the same storage time.Results:The TNC count(r4℃=-0.9588,r20-24℃=-0.9790),TNC viability(r4℃=-0.9941,r20 24 ℃=-0.9970),CD34+cells viability(r4℃=-0.9932,r20-24℃=-0.9828)of cord blood stored in cold storage(4 ℃)and room temperature storage(20-24 ℃)showed a consistent downward trend with the prolongation of storage time.The percentage of viable CD34+cells(r4℃=0.9169,r20-24 ℃=0.7470)and CFU-GM count(r4℃=-0.2537,r20-24℃=-0.8098)did not show consistent trends.When the storage time was the same,the TNC count,TNC viability,CD34+cells viability and CFU-GM count of cord blood stored in cold storage were higher than those stored at room temperature.Under the same storage time(24,36,48,60 or 72 h),TNC viability in room temperature storage was significantly lower than that in cold storage(P＜0.001),but TNC count,percentage of viable CD34+cells and CFU-GM count were not significantly different between room temperature storage and cold storage.When stored at room temperature for 24 h and 36 h,the viability of CD34+cells was significantly lower than that in cold storage(P＜0.001,P＜0.01),when the storage time for 48,60 and 72 h,there was no significant difference in the CD34+cells viability between room temperature storage and cold storage.Conclusion:It is recommended that cord blood be stored in cold storage(4 ℃)from collection to preparation,and processed as soon as possible.

Objective:To analyze the genotypes distribution of common and rare thalassemia in people of reproductive age in Huadu district of Guangzhou,enhance the database of thalassemia.Methods:Peripheral blood samples were collected for genotype analysis in Maternity and Child Health Hospital of Huadu District from January 2016 to October 2022.Gap-PCR and Reverse dot blot hybridization were used to detect common thalassemia genotypes.DNA sequencing was performed in samples suspected of rare genotypes.Results:A total of 16 171 subjects were identified as thalassemia carriers,and the positive rate was 44.41％(16 171/36 412).The genotypes of 114 cases(0.31％)were rare.A total of 10 845 cases were identified as α-thalassemia carriers(29.78％),and--SEA/αα was the most common genotype in those people,followed by-α3.7/αα and-α4.2/αα.A total of 4 531 subjects were identified as common β-thalassemia carriers(12.44％).The most common β-thalassemia mutation in the population was β41-42/βN,followed by β654/βN and β-28/β N.A total of 681 subjects were identified as αβ thalassemia carriers(1.87％),among them--SEA/αα compounded withβ CD41-42/β N was the most common genotype.A total of 48 cases were identified as rare α-thalassemia carriers,14 types of mutations,in which Fusion gene/αα was the most common.A total of 52 cases were identified as rare β-thalassemia carriers,11 types of mutation,in which βSEA-HPFH/βN was the most common.Conclusion:The thalassemia genotypes in Huadu district are complex and diverse.We should attach great importance to the detection of rare thalassemia genotypes.

Purpose: This study evaluated the value of contrast-enhanced ultrasonography (CEUS) in the ultrasound-guided microwave ablation (MWA) treatment of symptomatic focal uterine adenomyosis. Methods: This retrospective study was conducted between March 2020 and January 2023, enrolling 52 patients with symptomatic focal uterine adenomyosis who had undergone MWA. All patients were examined with CEUS before and after MWA. The non-perfused volume (NPV) was compared between CEUS and dynamic contrast-enhanced magnetic resonance imaging (DCEMRI) following ablation. Therapeutic efficacy and safety were evaluated at 3-, 6-, and 12-month follow-ups. Additionally, this study explored the correlations between pre-treatment CEUS features and a volume reduction ratio indicating sufficient ablation, defined as 50% or more at the 3-month follow-up. Results: No significant differences in NPV were noted between CEUS and DCE-MRI immediately after MWA and during follow-up (all P>0.05). At the 3-month follow-up, the median VRRs for the uterus and adenomyosis were 33.2% and 63.9%, respectively. Sufficient ablation was achieved in 69.2% (36/52) of adenomyosis cases, while partial ablation was observed in the remaining 30.8% (16/52). The identification of non-enhancing areas on pre-treatment CEUS was associated with sufficient ablation (P=0.016). At the 12-month follow-up, significant decreases were observed in both the uterine and adenomyosis volumes (all P<0.001). Dysmenorrhea and menorrhagia were significantly alleviated at 12 months, and no major complications were encountered. Conclusion CEUS can be used to evaluate the ablation zone of focal adenomyosis that has been treated with MWA, similarly to DCE-MRI. The identification of non-enhancing areas on pretreatment CEUS indicates satisfactory treatment outcomes.

Objective:To evaluate the effect of preoperative cognitive training on postoperative neurocognitive function in elderly patients undergoing coronary artery bypass grafting (CABG) and/or valve surgery.Methods:Seventy-four elderly patients of either sex, of American Society of Anesthesiologists Physical Status classification Ⅲ or Ⅳ, aged 60-90 yr, with body mass index of 19-28 kg/m 2, scheduled for elective CABG or valve surgery under general anesthesia, were divided into 2 groups ( n=37 each) using a computer-generated random number table method: cognitive training group (group CT) and control group (group C). Group CT was instructed to complete a cognitive training once 1 h per day for 5 consecutive days prior to surgery. Group C did not receive any cognitive training before surgery, and routine nursing was performed. At the 7th day after surgery, the patients′ neurocognitive function was evaluated by the Montreal Cognitive Assessment Scale(MoCA), the Postoperative Quality Recovery Scale (PQRS) was used to assess the patients′ recovery status, and the postoperative complications and morality in both groups were recorded. The patients were assessed using the Geriatric Depression Scale, MoCA and PQRS at the 1st month and 3rd month after operation. Results:The MoCA scores were significantly higher at the 7th day, 1st month and 3rd month postoperatively than in group C ( P<0.05). There was no significant difference in the postoperative case fatality rate and incidence of complications between the two groups ( P>0.05). Significant difference was observed in PQRS scores between the two groups at the 7th day after surgery ( P<0.05), but there were no significant differences in the PQRS scores and Geriatric Depression Scale scores between the two groups at the 1st month and 3rd month after operation ( P>0.05). Conclusions:The cognitive training can improve postoperative neurocognitive function in elderly patients undergoing CABG and/or valve surgery.

Objective:To analyze the effectiveness and interobserver agreement of the Parer five-tier, the National Institute of Child Health and Human Development (NICHD) three-tier, and the International Federation of Gynecology and Obstetrics (FIGO) three-tier electronic fetal monitoring (EFM) systems in identification of neonatal acidosis during labor.Methods:This retrospective study was conducted on full-term singleton cephalic deliveries with neonatal acidosis (umbilical artery blood gas pH≤7.1) and normal newborns (umbilical artery blood gas pH≥7.2) in the Nanjing Drum Tower Hospital, Nanjing University Medical School from January to December 2020. EFM tracings during the last 30-60 min before delivery were collected. Four obstetricians independently described the features of randomly sorted and coded EFM tracings. Another obstetrician categorized these tracings using the NICHD three-tier, FIGO three-tier, and Parer five-tier evaluation systems based on the features. All researchers were masked to the clinical characteristics and maternal and neonatal outcomes. The sensitivity and specificity for identifying neonatal acidosis, as well as the interobserver agreement, were analyzed for all three systems. Independent sample t-test, Chi-square (or Fisher's exact test) and Mann-Whitney U tests were used for statistical analysis. Inter-group comparisons of sensitivity and specificity between the three evaluation systems were assessed using McNemar's test. The Kappa statistic was used to analyze interobserver agreement. Results:This study included a total of 3 558 cases. After propensity score matching, there were 44 cases of neonatal acidosis and 78 control cases. There were no significant differences in parity, gestational weeks, modes of delivery, placental abruption, or analgesia rates between the two groups. The rates of instrumental vaginal delivery and neonatal intensive care unit (NICU) admission in the acidosis group were significantly higher than those in the control group [15.8% (7/44) vs. 2.6% (2/78), χ2=8.45, P=0.003; 31.8% (14/44) vs. 12.8% (10/78), χ2=8.45, P=0.004], while the umbilical artery blood pH and mean base excess were lower in the acidosis group than in the control group [7.04±0.07 vs. 7.30±0.05, t=4.98; (－12.40±3.32) vs. (－5.64±1.95) mmol/L, t=13.61; both P<0.001]. (2) Using the NICHD three-tier system, 95.5% (42/44) of the acidosis cases and 89.7% (70/78) of the control cases were classified as having category Ⅱ EFM tracings, indicating potential fetal acid-base imbalance; category Ⅲ EFM tracings were only observed in 4.5% (2/44) of the cases in the acidosis group. With the FIGO three-tier system, 81.8% (36/44) of the acidosis cases were categorized as having "pathological" tracings, and with the Parer five-tier system, 86.4% (38/44) of the acidosis cases were correctly classified into the "orange or red" risk zones that indicated acid-base imbalance. Among the control cases, there were 28.2% (22/78) with EFM tracings of "normal patterns" categorized by the FIGO three-tier system, and 41.0% (32/78) classified into the "green or blue" risk zones by the Parer five-tier system, which indicated good fetal conditions. None of the acidosis cases were misdiagnosed as being normal by the Parer five-tier system. (3) Compared with the NICHD three-tier system, both the FIGO three-tier and the Parer five-tier systems showed increased diagnostic sensitivity [4.5% (1.2%- 14.5%) vs. 81.8% (66.8%-89.4%) and 86.4% (71.8%-92.4%)], but decreased specificity [100.0% (95.3%- 100.0%) vs. 87.2% (78.0%-92.9%) and 84.6% (75.0%-91.0%)]. There was no statistically significant difference in the sensitivity or specificity between the FIGO three-tier and Parer five-tier systems for identifying neonatal acidosis ( P=0.727 and 0.791). (4) When reading the tracings of control cases, the total agreement rate for the NICHD three-tier system by different observers was as high as 94.2%, while the total agreement rates for the FIGO three-tier and Parer five-tier systems were 69.7% and 67.7%, respectively. In the interpretation of EFHR tracings for acidosis cases, the interobserver agreement for the Parer five-tier system was excellent [Kappa (95% CI): 0.87 (0.79-0.95)], while both the NICHD three-tier and FIGO three-tier systems showed good agreement [Kappa (95% CI): 0.77 (0.66-0.88) and 0.72 (0.60-0.84)]. Conclusions:The Parer five-tier and the FIGO three-tier systems have higher sensitivity in identifying neonatal acidosis than the NICHD three-tier system, and the Parer five-tier system achieves a higher negative predictive value and a greater agreement in the interpretation of pathological EFM patterns.

Objective:To establish a scoring system for preoperative prediction of the malignant potential of gastric stromal tumors based on gastroscopic and endoscopic ultrasound features, along with validation.Methods:A total of 286 patients who were treated in Jiangsu Province Hospital of Chinese Medicine from January 1, 2017 to December 31, 2023 and diagnosed as having gastric stromal tumors by postoperative pathology were enrolled in the modeling group. According to National Institutes of Health classification system, 227 very-low/low-risk patients were classified into the low malignant potential (LMP) group, and the 59 intermediate/high-risk patients into the high malignant potential (HMP) group. LASSO regression analysis was performed to identify predictive factors for HMP gastric stromal tumors, and a nomogram prediction model was developed. Internal validation using the Bootstrap method was performed on the modeling group, and external validation was performed on data from 85 patients who were treated and diagnosed as having gastric stromal tumors by postoperative pathology in Taizhou People's Hospital from January 1, 2021 to December 31, 2023. The receiver operator characteristic (ROC) curves, calibration curves, and decision curve analyses were employed in both the modeling and external validation groups.Results:Tumor size (coef=0.755), tumor shape (coef=0.015), tumor location (coef=0.008), growth pattern (coef=-0.026), cystic change (coef=0.685), and surface unceration change (coef=-0.545) were the independent predictive factors for HMP gastric stromal tumors. The nomogram-based prediction model constructed using these factors achieved an area under the ROC curve of 0.959 (95% CI: 0.898-0.903) in the modeling group and 0.959 (95% CI: 0.857-1.000) in the external validation group. The model demonstrated good accuracy (0.917) and a Kappa value of 0.737 in internal validation. Calibration curve and decision curve analyses indicated strong calibration and high net benefit in both the modeling and the external validation groups. Conclusion:Tumor size, tumor shape, tumor location, growth pattern, cystic change, and surface ulceration change are independent predictive factors for HMP gastric stromal tumors. The nomogram model developed based on these factors offers effective and convenient visualization for clinicians to predict the malignant potential of gastric stromal tumors preoperatively.