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.

Umbilical cord mesenchymal stem cells (UC-MSCs) have been widely used in regenerative medicine, but there is limited research on the stability of UC-MSCs formulation during production. This study aims to assess the stability of the cell stock solution and intermediate product throughout the production process, as well as the final product following reconstitution, in order to offer guidance for the manufacturing process and serve as a reference for formulation reconstitution methods. Three batches of cell formulation were produced and stored under low temperature (2-8 ℃) and room temperature (20-26 ℃) during cell stock solution and intermediate product stages. The storage time intervals for cell stock solution were 0, 2, 4, and 6 h, while for intermediate products, the intervals were 0, 1, 2, and 3 h. The evaluation items included visual inspection, viable cell concentration, cell viability, cell surface markers, lymphocyte proliferation inhibition rate, and sterility. Additionally, dilution and culture stability studies were performed after reconstitution of the cell product. The reconstitution diluents included 0.9% sodium chloride injection, 0.9% sodium chloride injection + 1% human serum albumin, and 0.9% sodium chloride injection + 2% human serum albumin, with dilution ratios of 10-fold and 40-fold. The storage time intervals after dilution were 0, 1, 2, 3, and 4 h. The reconstitution culture media included DMEM medium, DMEM + 2% platelet lysate, 0.9% sodium chloride injection, and 0.9% sodium chloride injection + 1% human serum albumin, and the culture duration was 24 h. The evaluation items were viable cell concentration and cell viability. The results showed that the cell stock solution remained stable for up to 6 h under both low temperature (2-8 ℃) and room temperature (20-26 ℃) conditions, while the intermediate product remained stable for up to 3 h under the same conditions. After formulation reconstitution, using sodium chloride injection diluted with 1% or 2% human serum albumin maintained a viability of over 80% within 4 h. It was observed that different dilution factors had an impact on cell viability. After formulation reconstitution, cultivation in medium with 2% platelet lysate resulted in a cell viability of over 80% after 24 h. In conclusion, the stability of cell stock solution within 6 h and intermediate product within 3 h meets the requirements. The addition of 1% or 2% human serum albumin in the reconstitution diluent can better protect the post-reconstitution cell viability.

The growth of three plague phages from Qinghai Plateau in two Yersinia pestis strains(plague vaccine strains EV76 and 614F)and four non-Yersinia pestis strains(Yersinia pseudotuberculosis PTB3,PTB5,Escherichia coli V517,and Yersinia enterocolitica 52302-2)were detected through a micromethod based on the OmniLogTM microbial identification system and by the drop method,to provide a scientific basis for future ecological studies and classification based on the host range.For plague vaccine strains EV76 and 614F,successful phage infection and subsequent phage growth were observed in the host bacte-rium.Diminished bacterial growth and respiration and a concomitant decrease in color were observed with the OmniLogTM mi-crobial identification system at 33 ℃ for 48 h.Yersinia pseudotuberculosis PTB5 was sensitive to Yersinia pestis phage 476,but Yersinia pseudotuberculosis PST5 was insensitive to phage 087 and 072204.Three strains of non-Yersinia pestis(Yersinia pseudotuberculosis PTB3,Escherichia coli V517,and Yersinia enterocolitica 52302-2)were insensitive to Yersinia pestis pha-ges 087,072204,and 476 showed similar growth curves.The growth of phages 476 and 087,as determined with the drop method,in two Yersinia pestis strains(plague vaccine strains EV76 and 614F)and four non-Yersinia pestis strains(Yersinia pseudotuberculosis PTB3,Escherichia coli V517,and Yersin-ia enterocolitica 52302-2)showed the same results at 37 ℃,on the basis of comparisons with the OmniLogTM microbial i-dentification system;in contrast,phages 072204 did not show plaques on solid medium at 37 ℃ with plague vaccine strains EV76 and 614F.Determination based on the OmniLogTM detection system can be used as an alternative to the traditional determination of the host range,thus providing favorable application val-ue for determining the interaction between the phage and host bacteria.

Objective The aim of this study was to investigate the prospective association between physical activity (PA),independently or in conjunction with other contributing factors,and osteoporosis (OP) outcomes. Methods The Physical Activity in Osteoporosis Outcomes (PAOPO) study was a community-based cohort investigation. A structured questionnaire was used to gather the participants' sociodemographic characteristics. Bone mineral density (BMD) measurements were performed to assess OP outcomes,and the relationship between BMD and OP was evaluated within this cohort. Results From 2013 to 2014,8,471 participants aged 18 years and older were recruited from Tangshan,China's Jidong community. Based on their PA level,participants were categorized as inactive,moderately active,or very active. Men showed higher physical exercise levels than women across the activity groups. BMD was significantly higher in the very active group than in the moderately active and inactive groups. Individuals aged>50 years are at a higher risk of developing OP and osteopenia. Conclusion The PAOPO study offers promising insights into the relationship between PA and OP outcomes,encouraging the implementation of PA in preventing and managing OP.

Objective To observe the therapeutic effect of Tiaowei Heying Xuanbi Prescription combined with conventional western medicine on the recurrence of angina pectoris after percutaneous coronary intervention(PCI)for coronary heart disease(CHD).Methods Ninety patients with recurrent angina pectoris of congealing cold in the heart vessel type after PCI for CHD were randomly divided into a control group and a treatment group,with 45 patients in each group.The control group was treated with conventional western medicine,and the treatment group was additionally treated with Tiaowei Heying Xuanbi Prescription on the basis treatment for the control group.The course of treatment for the two groups covered 12 weeks.The changes of traditional Chinese medicine(TCM)syndrome score,angina efficacy score,Seattle Angina Questionnaire(SAQ)score,left ventricular ejection fraction(LVEF)and interventricular septal thickness(IVS)in the two groups were observed before and after the treatment.And after treatment,the clinical efficacy and safety of the two groups were evaluated.Results(1)Both of the control group and treatment group had one case dropped out during the trial,and eventually 44 patients in each of the two groups were included in the efficacy statistics.(2)After 12 weeks of treatment,the total effective rate of the treatment group was 93.18%(41/44),and that of the control group was 81.82%(36/44).The intergroup comparison(tested by chi-square test)showed that the curative effect of the treatment group was significantly superior to that of the control group(P＜0.05).(3)After treatment,the scores of angina attack score,duration of angina,pain level,and nitroglycerin dosage as well as the overall angina efficacy scores in the two groups were significantly lower than those before treatment(P＜0.05),and the scores of each item as well as overall angina efficacy scores of the treatment group were significantly lower than those of the control group after treatment(P＜0.05).(4)After treatment,the SAQ item scores of physical limitation(PL),angina stability(AS),angina frequency(AF),treatment satisfaction(TS),and disease perception(DS)in the two groups were significantly increased than those before treatment(P＜0.05),and the scores of each SAQ item in the treatment group were significantly higher than those in the control group after treatment(P＜0.05).(5)After treatment,the symptom scores of chest pain,chest tightness,shortness of breath,fatigue,and dark purple lips in both groups were significantly lower than those before treatment(P＜0.05),and the TCM syndrome scores of the treatment group were significantly lower than those of the control group after treatment(P＜0.05).(6)The results of echocardiography showed that after treatment,the LVEF of the two groups of patients was improved compared with that before treatment(P＜0.05),while no obvious change of IVS in the two groups was presented before and after treatment(P＞0.05).The intergroup comparison showed that the improvement of LVEF in the treatment group was significantly superior to that of the control group(P＜0.05).(7)During the treatment,the incidence rate of adverse events in the treatment group was 2.27%(1/44)and that in the control group was 18.18%(8/44),and the difference was not statistically significant when compared between the two groups(P＞0.05).There were no significant changes in the safety indexes associated with the blood,urine,and stool routine test,liver function,renal function,and electrocardiogram in the two groups.Conclusion Tiaowei Heying Xuanbi Prescription combined with conventional western medicine can effectively alleviate the clinical symptoms of patients with recurrent angina pectoris of congealing cold in the heart vessel type after PCI for CHD,and improve the patients'TCM syndromes and left ventricular ejection fraction,with remarkable clinical efficacy.

Objective To explore the clinical efficacy of low molecular weight heparin combined with insulin in the treatment of hyper-triglyceridemic-acute pancreatitis(HTG-AP).Methods A total of 106 patients diagnosed with HTG-AP who were admitted to the department of gastroenterology of Huaibei People's Hospital from May 2022 to July 2023 were selected as the research objects.According to the random number table method,the low-molecular heparin group(35 cases,received a 5 000 U subcutaneous injection low-molecular heparin once every 12 hours for 6 days),the insulin group(35 cases,received intravenous insulin pumping at a rate of 2 U/h,with careful monitoring of the patient's random blood glucose levels to prevent hypoglycemia),and the combination therapy group(36 cases,received both low-molecular heparin and insulin).Before treatment and at 1,2,and 6 days after treatment,the difference of serum triacylglycerol(TG),total cholesterol(TC),blood amylase,inflammatory factors[C-reactive protein(CRP),interleukin-6(IL-6)],calcium ions,and creatinine levels among the three groups were compared.The modified computed tomography severity index(MCTSI)scores,acute physiology and chronic health evaluationⅡ(APACHEⅡ),hospital length of stay,and hospital costs before and after 6 days of treatment were observed.Results After treatment,the TC of all three groups significantly decreased compared to before treatment(P<0.05),but there was no significant difference among the three groups.The calcium ion levels of the three groups did not show a statistically significant difference before and after treatment.After 6 days of treatment,the creatinine levels of the three groups significantly decreased compared to before treatment,but there was no significant difference among the three groups.After 2 days of treatment,serum TG levels were significantly lower in the combination therapy group and insulin group compared to the low-molecular heparin group(mmol/L:4.6±1.7,4.4±1.8 vs.5.6±2.0,both P<0.05).However,there was no statistically significant difference between the combination therapy group and the insulin group.After 6 days of treatment,the combination therapy group showed significantly lower levels of serum TG,blood amylase,CRP,and IL-6 compared to the insulin group and the low-molecular heparin group[TG(mmol/L):2.8±1.9 vs.4.3±1.9,5.0±2.2,blood amylase(U/L):36.0(32.0,45.0)vs.59.0(43.0,71.0),52.0(45.0,64.0),CRP(mg/L):12.9(8.8,29.7)vs.35.3(21.7,50.3),31.4(23.0,45.1),IL-6(ng/L):15.4(9.8,23.5)vs.25.6(16.4,51.5),32.9(14.7,41.4),all P<0.05].After 6 days of treatment,the APACHEⅡscores of all three groups decreased significantly(all P<0.05).The MCTSI scores of the insulin group and the combined treatment group also decreased significantly compared to before treatment.Furthermore,the MCTSI and APACHEⅡscores of the combination therapy group were significantly lower than those of the low-molecular heparin group and the insulin group(MCTSI score:2.3±0.7 vs.3.3±1.7,2.9±1.3,APACHEⅡscore:1.3±1.2 vs.2.5±2.4,2.6±2.5,all P<0.05).The combination therapy group had significantly lower length of hospital stay and treatment cost compared to the low molecular heparin and insulin groups[length of hospital stay(days):6.9±1.6 vs.8.8±3.4,8.5±2.8,and cost of treatment(yuan):6 040.5(5 239.4,7 105.9)vs.6 696.4(5 791.5,11 026.2),6 918.5(6 087.9,10 080.8),all P<0.05].Conclusions The combination of low-molecular heparin and insulin treatment can significantly reduce serum TG and inflammatory factor levels,as well as the severity and duration of the disease.This approach can also reduce the cost of treatment.Therefore,it is worth promoting and applying in clinical settings.

Bone organoids can simulate the complex structure and function of the bone tissues, which makes them a frontier technology in organoid researches. Bone organoids show a tremendous potential of applications in bone disease modeling, bone injury repair, and medicine screening. Although advancements have been made so far in constructing bone organoids with functional structures like mineralization, bone marrow, trabecular bone, callus, woven bone, etc, the researches in this field are confronted with numerous challenges such as lack of standardized construction strategies and unified evaluation criteria, which limits their further promotion and application. To standardize researches in bone organoids, the Orthopedic Expert Committee of Geriatric Branch of Chinese Association of Gerontology and Geriatrics, the Youth Osteoporosis Group of Orthopedic Branch of Chinese Medical Association, the Osteoporosis Group of Orthopedic Surgeon Branch of Chinese Medical Doctor Association, and the Osteoporosis Committee of Shanghai Association of Integrated Traditional Chinese and Western Medicine organized related experts to formulate Expert consensus on the construction, evaluation, and application of bone organoids ( version 2024) based on an evidence-based approach. A total of 17 recommendations were put forth, aiming to standardize researches and clinical applications of bone organoids and enhance their value in scientific research and clinical practice.

Objective To investigate the clinical characteristics and prognosis of pneumococcal meningitis(PM),and drug sensitivity of Streptococcus pneumoniae(SP)isolates in Chinese children.Methods A retrospective analysis was conducted on clinical information,laboratory data,and microbiological data of 160 hospitalized children under 15 years old with PM from January 2019 to December 2020 in 33 tertiary hospitals across the country.Results Among the 160 children with PM,there were 103 males and 57 females.The age ranged from 15 days to 15 years,with 109 cases(68.1% )aged 3 months to under 3 years.SP strains were isolated from 95 cases(59.4% )in cerebrospinal fluid cultures and from 57 cases(35.6% )in blood cultures.The positive rates of SP detection by cerebrospinal fluid metagenomic next-generation sequencing and cerebrospinal fluid SP antigen testing were 40% (35/87)and 27% (21/78),respectively.Fifty-five cases(34.4% )had one or more risk factors for purulent meningitis,113 cases(70.6% )had one or more extra-cranial infectious foci,and 18 cases(11.3% )had underlying diseases.The most common clinical symptoms were fever(147 cases,91.9% ),followed by lethargy(98 cases,61.3% )and vomiting(61 cases,38.1% ).Sixty-nine cases(43.1% )experienced intracranial complications during hospitalization,with subdural effusion and/or empyema being the most common complication[43 cases(26.9% )],followed by hydrocephalus in 24 cases(15.0% ),brain abscess in 23 cases(14.4% ),and cerebral hemorrhage in 8 cases(5.0% ).Subdural effusion and/or empyema and hydrocephalus mainly occurred in children under 1 year old,with rates of 91% (39/43)and 83% (20/24),respectively.SP strains exhibited complete sensitivity to vancomycin(100% ,75/75),linezolid(100% ,56/56),and meropenem(100% ,6/6).High sensitivity rates were also observed for levofloxacin(81% ,22/27),moxifloxacin(82% ,14/17),rifampicin(96% ,25/26),and chloramphenicol(91% ,21/23).However,low sensitivity rates were found for penicillin(16% ,11/68)and clindamycin(6% ,1/17),and SP strains were completely resistant to erythromycin(100% ,31/31).The rates of discharge with cure and improvement were 22.5% (36/160)and 66.2% (106/160),respectively,while 18 cases(11.3% )had adverse outcomes.Conclusions Pediatric PM is more common in children aged 3 months to under 3 years.Intracranial complications are more frequently observed in children under 1 year old.Fever is the most common clinical manifestation of PM,and subdural effusion/emphysema and hydrocephalus are the most frequent complications.Non-culture detection methods for cerebrospinal fluid can improve pathogen detection rates.Adverse outcomes can be noted in more than 10% of PM cases.SP strains are high sensitivity to vancomycin,linezolid,meropenem,levofloxacin,moxifloxacin,rifampicin,and chloramphenicol.[Chinese Journal of Contemporary Pediatrics,2024,26(2):131-138]

Objective:To explore the clinical manifestations,diagnosis,pathological features and treatment of small-cell carci-noma of the prostate(SCCP).Methods:We conducted a retrospective analysis of the clinical and pathological data of 2 cases of confirmed SCCP treated from November 2017 to March 2018,and reviewed relevant literature.Results:Both the patients had the symptoms of frequent,urgent and difficult urination,with an elevated level of PSA and grades Ⅱ-Ⅲ enlargement of the prostate at palpation.One underwent prostate puncture biopsy and the other received transurethral 1470 laser vaporization resection of the tumor.Postoperative pathology indicated prostate adenocarcinoma accompanied by SCCP in both of the cases.One of them was treated by eto-poside-platinum(EP)chemotherapy and died of systemic multiple organ failure 20 months after diagnosis,while the other underwent endocrine therapy and has lived with tumor up to the present day.Conclusion:The incidence rate of SCCP is low,its malignancy is high,and its prognosis is poor.The average survival of the patient is about 7 to 10 months after diagnosis.Currently there is no effec-tive management of the dissease,except by relying on the experience of the treatment of small-cell lung cancer,with chemotherapy as the main option.

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.