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 analyze the epidemiological distribution,microbiological characteristics,drug-resistance status,and risk factors for mortality in adult intensive care unit(ICU)patients with Klebsiella pneumoniae infection.Methods This multi-center prospective cohort study included ICU patients with suspected infection from 67 hospitals across 16 Chinese provinces/municipalities between July 1,2021 and December 31,2022.Clinical data and microbiological results were collected,and patients were divided into survival and non-survival groups according to their survival status and drug-resistance situation.Risk factors for mortality and drug resistance in ICU patients with Klebsiella pneumonia infection were determined through univariate and multivariate logistic regression analyses.Results A total of 2964 ICU-infected patients were enrolled,with 12 175 microbial specimens submitted for testing.Among these,487 specimens tested positive for Klebsiella pneumoniae.Ultimately,314 patients with Klebsiella pneumoniae infection were identified,primarily from lung infections,with a drug-resistance rate of 78.3%.The in-hospital mortality rate of ICU patients infected with Klebsiella pneumoniae was 19.8%.Univariate and multivariate logistic regression analyses revealed that older age(P=0.027),high drug-resistance rate(P=0.028),and low clinical-effectiveness rate(P<0.001)were independent risk factors for mortality in ICU patients infected with Klebsiella pneumoniae.Drug-resistance analysis showed that,compared with non-resistant cases,ICU patients with drug-resistant Klebsiella pneumoniae infection had lower pathogen-clearance rates(P=0.003),clinical-effectiveness rates(P=0.004),and antibiotic-effectiveness rates(P<0.010),and higher mortality rates(P=0.006).Patients with Klebsiella pneumoniae abdominal infection(P=0.003)and urinary tract infection(P=0.007)had higher drug-resistance incidences.There were no statistically significant differences in clinical-effectiveness rate,Klebsiella pneumoniae clearance,drug-resistance incidence,mortality rate,or hospital-stay length between patients with lung infection and those with non-lung infection of Klebsiella pneumoniae(P>0.05).Compared with patients with non-bloodstream infection,patients with bloodstream infection of Klebsiella pneumoniae had lower clinical-effectiveness rates(P=0.027)and higher mortality rates(P=0.021).Conclusions Older age,high drug-resistance rate,and low clinical-effectiveness rate are independent risk factors for mortality in ICU patients infected with Klebsiella pneumoniae.ICU patients with bloodstream infection of Klebsiella pneumoniae may have lower clinical-effectiveness rates and higher mortality rates.ICU patients with abdominal and urinary tract infections caused by Klebsiella pneumoniae are more likely to develop drug resistance.

OBJECTIVE To investigate the quality and management of cleaning and disinfection of soft endoscopes in Wuxi hospitals,to analyze the existing problems and put forward suggestions for improvement,and to provide references for endoscope-related infection in hospitals.METHODS From Sep.to Nov.2024,the cleaning and disin-fection status and managements of soft endoscopes were investigated.Endoscopes were sampling for adenosine triphosphate(ATP)biofluorescence and bacteriological testing;final rinsing water,hands of disinfection person-nels,disinfectants and environmental surfaces were collected for bacteriological testing.RESULTS Totally 68.18％of hospitals performed daily leaks test before cleaning,and 81.82％used o-Phthalaldehyde;81.25％of hospitals used peracetic acid in endoscopy sterilization,with only 1 hospital using glutaraldehyde.Totally 86.36％of hospi-tals monitored the concentration of disinfectants before daily works.There were statistically significant differ-ences in full-time,education levels,age and working experience of personnels among different levels of hospitals(P＜0.05).The pass rate of the 60 endoscope ATP specimens was 88.33％,and there were statistically signifi-cant differences in the pass rate of gastroscopic ATP testing among different levels of hospitals(P=0.032).The qualification status differed significantly in the types of endoscopes and the time length of enzyme washing(P＜0.05).All 60 endoscopic bacteriological samples were qualified,while 141 environmental bacteriological samples were with a pass rate of 94.33％.Unqualified samples were mainly for disinfection personnel's hands,rinse tank faucets,final rinse water.Rolestonella piercei and Staphylococcus wolffii were detected in one failed final rinse wa-ter by mass spectrometry.CONCLUSIONS The overall equipment and staffing of the surveyed endoscope centers(rooms)basically meet operational needs and generally follow endoscope cleaning and disinfection guidelines.However,there are still deficiencies in cleaning and disinfection management,equipment maintenance,disinfect-ant concentration monitoring and personnel training.Further efforts are needed to strengthen the disinfection quali-ty monitoring of endoscope and related factors.

Objective To reveal the scientific output and trends in pulmonary nodules/early-stage lung cancer prediction models. Methods Publications on predictive models of pulmonary nodules/early lung cancer between January 1, 2002 and June 3, 2023 were retrieved and extracted from CNKI, Wanfang, VIP and Web of Science database. CiteSpace 6.1.R3 and VOSviewer 1.6.18 were used to analyze the hotspots and theme trends. Results A marked increase in the number of publications related to pulmonary nodules/early-stage lung cancer prediction models was observed. A total of 12581 authors from 2711 institutions in 64 countries/regions published 2139 documents in 566 academic journals in English. A total of 282 articles from 1256 authors were published in 176 journals in Chinese. The Chinese and English journals which published the most pulmonary nodules/early-stage lung cancer prediction model-related papers were Journal of Clinical Radiology and Frontiers in Oncology, respectively. Chest was the most frequently cited journal. China and the United States were the leading countries in the field of pulmonary nodules/early-stage lung cancer prediction models. The institutions represented by Fudan University had significant academic influence in the field. Analysis of keywords revealed that multi-omics, nomogram, machine learning and artificial intelligence were the current focus of research. Conclusion Over the last two decades, research on risk-prediction models for pulmonary nodules/early-stage lung cancer has attracted increasing attention. Prognosis, machine learning, artificial intelligence, nomogram, and multi-omics technologies are both current hotspots and future trends in this field. In the future, in-depth explorations using different omics should increase the sensitivity and accuracy of pulmonary nodules/early-stage lung cancer prediction models. More high-quality future studies should be conducted to validate the efficacy and safety of pulmonary nodules/early-stage lung cancer prediction models further and reduce the global burden of lung cancer.

Objective:To investigate the efficacy and toxicity of blinatumomab in the first-line and second-line treatment of pediatric B-cell acute lymphoblastic leukemia (B-ALL).Methods:A multi-center retrospective cohort study was conducted to analyze clinical data from 323 pediatric B-ALL patients treated with blinatumomab across 14 hospitals in China from May 2021 to July 2023. Patients were divided into four groups based on the treatment phase and disease status when blinatumomab was used: relapsed/refractory group, post-consolidation minimal residual disease (MRD)-positive group, early MRD-positive group, and MRD-negative group. Blinatumomab for the relapsed/refractory group was considered as second-line treatment, while the other 3 groups as first-line treatment. The MRD negativity rate after treatment, the survival rates and the incidence of severe adverse events were compared across these groups. Patients who received blinatumomab for more than 7 days were included in the efficacy analysis. Survival analysis was performed using the Kaplan-Meier method, and Log-Rank test was used to compare the survival rates among groups.Results:Among the 323 patients, 191 (59.1%) were male, with the age of 6.2 (3.9, 10.5) years. There were 117 patients in the relapsed/refractory group, 62 cases in the post-consolidation MRD-positive group, 43 cases in the early MRD-positive group, and 101 cases in the MRD negative group. In the relapsed/refractory group, the complete remission rate and MRD negativity rate after one course of blinatumomab were 71.4% (35/49) and 81.5% (75/92) for the 49 children without complete remission and the 92 children with flow cytometry-positive MRD, respectively. In the post-consolidation MRD-positive group, the MRD negativity rates after one course of blinatumomab were 100.0% (27/27), 12/16 and 9/19 for patients with MRD positivity detected by flow cytometry, polymerase chain reaction and next-generation sequencing, respectively. In the early MRD-positive group, the MRD negativity rates were 96.7% (29/30) and 9/9 for flow cytometry and next-generation sequencing, respectively. The 2-year overall survival rate and event-free survival rate for the 319 children evaluable for efficacy were (90.6±1.7)% and (87.6±1.9)%, respectively, with the relapsed/refractory group showing significantly lower overall survival rates and event-free survival rate compared to the other groups ( χ2=21.40, 26.21,both P<0.001). Grade 3 or higher adverse events occurred in 128 cases (39.6%), with hematological toxicity observed in 101 cases, while cytokine release syndrome (CRS), infection, and neurotoxicity occurred in 11, 26 and 8 cases, respectively. In addition, there were statistically significant differences in the grade 3 or higher CRS among the four groups ( χ2=8.03, P<0.05). Conclusion:Blinatumomab can clear MRD more effectively and achieve superior survival outcomes when used as first-line treatment for pediatric B-ALL, with less CRS.

Objective:To explore the neurophysiological features of the prefrontal-limbic-striatal circuit in patients with early-stage bipolar disorder without manic or hypomanic episodes, and its role in identifying early-stage bipolar disorder.Methods:From 2009 to 2019, a total of 155 hospitalized patients with major depressive disorder (MDD) from Nanjing Brain Hospital were selected after at least 5 years of follow-up, 31 patients with depression transitioned to bipolar disorder(ctBD group) and 76 patients remained the diagnosis of MDD(MDD group) were recruited.Sixty-two healthy controls matched for age, gender, and education years were selected as control group(HC group). Resting-state magnetoencephalography (MEG) data in eyes-open state of all subjects were collected.Data were analyzed based on the fieldtrip toolkit on the MATLAB platform. The key brain area of the prefrontal-limbic-striatal circuit were selected. Inter-group statistical analysis were conducted on the spectral energy and power-correlated functional connectivity at the theta, alpha, beta, and gamma frequency bands in the brain area of interest. In addition, the prediction model was constructed to early recognize bipolar disorder.Results:(1)There were statistically significant differences in the spectral energy of theta and alpha frequency bands in the prefrontal-limbic-striatal circuit among the 3 groups (cluster- F=120.50, 112.39, both P<0.05). The spectral energy of theta and alpha frequency bands in interest brain regions of prefrontal-limbic-striatal circuit in MDD group was lower than that in HC group (cluster- t=89.52, P<0.05). The spectral energy of theta band in prefrontal-limbic-striatal circuit in ctBD group was lower than that in HC group(cluster- t=105.82, P<0.05), and the spectral energy of alpha band in inferior frontal gyrus, orbitofrontal gyrus and caudate nucleus was lower than that in HC group (cluster- t=75.78, P<0.05), while there was no significant difference between the MDD group and the ctBD group ( P>0.05).(2)After FDR correction, there were statistically significant differences in functional connectivity between the left orbitofrontal gyrus and the right ventral striatum among the three groups (0.26 (0.13, 0.34), 0.12 (0.09, 0.24), 0.27 (0.20, 0.37), H=13.51, P<0.05, FDR correction). The strength of functional connectivity between the left orbitofrontal gyrus and the right ventral striatum in the MDD group was weaker than that in the HC group and the ctBD group (all P<0.05).(3)Binary Logistic regression analysis showed that the functional connectivity of beta frequency band between the left orbitofrontal gyrus and the right ventral striatum ( B=1.50, OR=4.50, 95% CI=1.73-11.70), the functional connectivity between the right orbitofrontal gyrus and the right amygdala( B=0.98, OR=2.68, 95% CI=1.18-6.13), the total HAMD score ( B=0.80, OR=2.28, 95% CI=1.36-3.67), the body weight factor score ( B=-1.99, OR=0.14, 95% CI=0.04-0.45), the anxiety factor score ( B=-0.99, OR=0.37, 95% CI=0.19-0.71), and sleep factor score( B=-1.14, OR=0.32, 95% CI=0.16-0.65)were the influencing factors for depression transitioned to bipolar disorder. Conclusion:The decreased resting low-frequency energy in the prefrontal-limbic-striatal circuit may be the common neural basis for the onset of unipolar and bipolar depression, and enhanced functional connectivity may be a potential neural circuit mechanism for depression transitioned to bipolar disorder. Functional connectivity combined with clinical manifestations is helpful for early recognition of bipolar disorder.

Objective:To investigate the clinical characteristics of patients with multiple myeloma(MM)complicated by bone lesions and the risk factors associated with bone lesions.Methods:The clinical data of 294 newly diagnosed MM patients in Gansu Provincial Hospital from January 2017 to June 2021 were retrospectively analyzed.The patients were divided into the bone lesion group(154 cases)and the non-bone lesions group(140 cases)based on the presence of absence of bone lesions at diagnosis.The general data and laboratory parameters were compared between the two groups.The risk factors for bone lesions in MM patients were analyzed by logistic regression analysis,and the characteristic(ROC)curves were plotted to assess the predictive value of each risk factor for the occurrence of bone lesions in MM patients.Results:Compared to the non-bone lesion group,the bone lesion group had significantly higher serum calcium levels and significantly greater proportions of patients with Durie-Salmon(DS)stage Ⅲ,and bone pain(all P＜0.05).Logistic regression analysis showed that elevated serum calcium(OR=5.135,95％CI:1.931-13.653,P=0.001),DS stage Ⅲ(OR=1.841,95％CI:1.019-3.328,P=0.043),and bone pain(OR=8.208,95％CI:4.761-14.151,P＜0.001)were independent risk factors for bone lesions in MM patients.ROC curve analysis showed that serum calcium(AUC=0.619,95％CI:0.555-0.683,P＜0.001)and bone pain(AUC=0.743,95％CI:0.692-0.793,P＜0.001)had predictive value for bone lesions in MM patients.Conclusion:MM patients have a high incidence of bone lesions,and active monitoring and management of risk factors may improve treatment outcomes and prognosis.

OBJECTIVE: To explore clinical efficacy of different technical combinations in treating ischemic diabetic foot (DF). METHODS: A retrospective analysis was conducted on 35 patients with DF who were treated with vascular interventional opening technique, periosteal distraction technique and bone cement coverage technique from January 2024 to November 2024. They were divided into comprehensive group and periosteal distraction group according to whether the vascular interventional opening technique was used in combination or not. There were 5 patients in comprehensive group, including 4 males and 1 female, aged from 59 to 73 years old with an average of (64.40±5.46) years old;the duration of diabetes ranged from 0.17 to 30.00 years with an average of (14.63±12.02) years;the courses of DF ranged from 30 to 150 days with an average of (84.00±61.48) days;2 patients were grade 2, 2 patients were grade 3, and 1 patient was grade 4 according to Wagner classification;combined vascular interventional opening, periosteal distraction and bone cement coverage surgery for treatment. There were 30 patients in periosteal stretch group, including 22 males and 8 females, aged from 58 to 86 years old with an average of (72.63±7.84) years old;the duration of diabetes was 10.00 (6.75, 16.75) years;the courses of DF was 30.00 (15.00, 37.50) days;14 patients were grade 2, 11 patients were grade 3, and 5 patients were grade 4 according to Wagner classification; combined periosteal distraction and bone cement coverage surgery for treatment. Changes of C-reactive protein (CRP), interleukin-6 (IL-6), and procalcitonin (PCT), toe skin temperature, peripheral capillary oxygen saturation (SpO₂), and visual analogue scale (VAS) for pain were compared between two groups before operation and 1 week after operation. The number of operations, healing period, healing number, toe amputation number, preoperative fever situation and the number of complications were compared between two groups. RESULTS: Both groups were followed up for at least 6 months. There were no statistically significant differences in the number of operations, healing period, toe amputation rate, wound healing rate and complications between two groups (P>0.05). Before operation, the toe skin temperature of comprehensive group (26.98±0.88) ℃ was lower than that of periosteal distraction group (28.17±1.45) ℃, and the difference was statistically significant (P<0.05);while there were no statistically significant difference in CRP, IL-6, PCT, toe SpO2 and VAS between two groups (P>0.05). At 1 week after operation, IL-6, toe skin temperature, toe SpO₂ and VAS in comprehensive group were 12.29(7.92, 22.15) pg·ml-1, (36.02±0.23) ℃, (95.80±0.84) % and(1.40±0.55) respectively, while those in periosteal distraction group were 5.49(4.36, 7.45) pg·ml^-1, (31.36±1.57) ℃, (84.53±6.38) %, (2.20±0.81);and there were statistically significant differences between two groups(P<0.05). CRP, IL-6 and VAS at 1 week after operation in both groups were decreased compared with those before operation, and the differences were statistically significant(P<0.05). The toe skin temperature and SpO₂ were increased compared with those before operation, and the differences were statistically significant(P<0.001). CONCLUSION The multi-technique combination therapy, including vascular interventional opening technique, periostealdistraction technique and bone cement covering technique, could protect each other, enhance efficacy, effectively promote the wound healing of ischemic diabetic foot ulcer, and reduce the toe amputation rate. For moderate to severe ischemic DF, the combined use of periosteal distraction and bone cement coverage techniques has a satisfactory effect. For extremely severe ischemic DF with inflow tract lesions, vascular interventional opening techniques need to be added.
Humans ; Male ; Female ; Middle Aged ; Aged ; Diabetic Foot/surgery* ; Retrospective Studies ; Aged, 80 and over ; Ischemia/surgery* ; Interleukin-6/metabolism*

With the rapid development of competitive sports, the incidence of anterior cruciate ligament (ACL) injury is on the rise. Such injuries may shorten athletes′ career and lead to other long-term adverse consequences. Although athletes generally recover well after ACL reconstruction, many still struggle to return to their pre-injury performance levels. Advances in the understanding of ACL anatomy and injury mechanisms, along with the evolution of surgical techniques and rehabilitation methods, have provided more individualized and tailored options for athletes following ACL injuries. However, there is currently no consensus in China regarding surgical and rehabilitation strategies for competitive athletes aiming to return to sports after ACL injuries. To this end, the Sports Medicine Committee of the Chinese Research Hospital Association and the Editorial Board of the Chinese Journal of Trauma jointly formulated the Expert consensus on surgical treatment and rehabilitation for competitive sports athletes returning to sports after anterior cruciate ligament injury ( version 2025), and presented 14 recommendations covering surgical indications, preoperative rehabilitation, surgical timing, surgical strategies and postoperative rehabilitation strategies, aiming to improve the surgical treatment and rehabilitation system for ACL injuries in competitive athletes and facilitate their return to high-level sports performance after injury.

Objective:To analyze the biological characteristics and genomic features of a Streptococcus pyogenes strain isolated from the pus of a child with an atypical brain abscess. Methods:The Streptococcus pyogenes strain, named 21SPY7071 ( emm22 type), was isolated from the brain abscess specimen of a child undergoing surgery for brain abscess. The biological characteristics of this strain were analyzed using blood agar culture, Gram staining, growth curve measurement, and hemolytic analysis. After whole-genome sequencing, core genome multilocus sequence typing (cgMLST) was performed to analyze the cgST type of the strain, and the distribution of virulence genes and drug resistance genes were analyzed. qRT-PCR was used to detect the differences in the expression of virulence genes at mRNA level between the strain 21SPY7071 and two Streptococcus pyogene strains of ATCC 19615 ( emm80 type) and GAS029 ( emm22 type, clinical isolate). Results:The strain 21SPY7071 was a Gram-positive Streptococcus with atypical weak β-hemolysis. Whole-genome sequencing and cgMLST revealed that this isolate belonged to the cgST type of 65937, containing 187 virulence genes and 97 drug resistance genes, with high sequence similarity (95.16%~100.00%) to the main virulence factor-encoding genes in the Virulence Factor Database. Compared with the strains of ATCC 19615 and GAS029, the strain 21SPY7071 showed reduced expression of genes encoding streptolysin S ( sagABCDEFGHI), streptolysin O ( slo), and hyaluronate lyase ( endA/ sdaB). Besides, compared with the strain ATCC 19615, the strain 21SPY7071 also showed decreased expression of virulence genes including speG, ideS/ mac, hylA, smeZ, lmb, and scpA/ scpB. Conclusion:This Streptococcus pyogenes strain isolated from the pus of a child with atypical brain abscess exhibits weak hemolysis and lower expression of virulence genes, which may be related to the mild clinical symptoms observed in the child.