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.

Using methylated pyrroloxicam as a starting material and following the principles of drug design such as bioisosterism and active site binding,we designed and synthesized ten structurally novel target compounds,whose structures were characterized by 1H NMR and MS analysis.The in vitro antitumor activity of these title compounds was evaluated by measuring their inhibitory activity against pancreatic cancer cells Capan-1,leukemia cells L1210,and human liver cancer cells SMMC-7721.The results showed that compound 6f(IC50=4.8±0.5 μmol/L)exhibited good inhibitory activity against Capan-1 pancreatic cancer cells,that compound 6b(IC50=2.6±0.3 μmol/L)showed good inhibitory activity against L1210 leukemia cells,and that compound 6c(IC50=2.1±0.2 μmol/L)displayed good inhibitory activity against SMMC-7721 human liver cancer cells.These preliminary results from the antitumor activity experiments suggest that the introduction of benzothiazine derivatives plays a certain role in enhancing the antitumor activity of this class of compounds.

Objective To understand the respiratory protection competency of staff in hospitals.Methods Staff from six hospitals of different levels and characteristics in Beijing were selected,including doctors,nurses,medical technicians,and servicers,to conduct knowledge assessment on respiratory protection competency.According to exposure risks of respiratory infectious diseases,based on actual cases and daily work scenarios,content of respira-tory protection competency assessment was designed from three aspects:identification of respiratory infectious di-seases,transmission routes and corresponding protection requirements,as well as correct selection and use of masks.The assessment included 6,6,and 8 knowledge points respectively,with 20 knowledge points in total,all of which were choice questions.For multiple-choice questions,full marks,partial marks,and no mark were given respective-ly if all options were correct,partial options were correct and without incorrect options,and partial options were correct but with incorrect options.Difficulty and discrimination analyses on question of each knowledge point was conducted based on classical test theory.Results The respiratory protection competency knowledge assessment for 326 staff members at different risk levels in 6 hospitals showed that concerning the 20 knowledge points,more than 60％participants got full marks for 6 points,while the proportion of full marks for other questions was relatively low.Less than 10％participants got full marks for the following 5 knowledge points:types of airborne diseases,types of droplet-borne diseases,conventional measures for the prevention and control of healthcare-associated infec-tion with respiratory infectious diseases,indications for wearing respirators,and indications for wearing medical protective masks.Among the 20 knowledge questions,5,1,and 14 questions were relatively easy,medium,and difficult,respectively;6,1,4,and 9 questions were with discrimination levels of ≥0.4,0.30-0.39,0.20-0.29,and ≤0.19,respectively.Conclusion There is still much room for hospital staff to improve their respiratory protection competency,especially in the recognition of diseases with different transmission routes and the indications for wearing different types of masks.

Objective To study the pharmacokinetic characteristics of lamotrigine tablets in Chinese healthy subjects under fasting and fed conditions,and to evaluate the bioequivalence and safety profiles between the domestic test preparation and the original reference preparation.Methods Twenty-four Chinese healthy male and female subjects were enrolled under fasting and fed conditions,18 male and 6 female subjects under fasting conditions,17 male and 7 female subjects under fed conditions.A random,open,single-dose,two preparations,two sequences and double-crossover design was used.Plasma samples were collected over a 72-hour period after give the test or reference preparations 50 mg under fasting and fed conditions.The concentration of lamotrigine in plasma was detected by liquid chromatography-tandem mass spectrometry,and the main pharmacokinetic parameters were calculated to evaluate the bioequivalence by WinNonLin 8.1 program.Results The main pharmacokinetic parameters of single-dose the tested and reference preparations were as follows:The fasting condition Cmax were(910.93±248.02)and(855.87±214.36)ng·mL-1;tmax were 0.50(0.25,4.00)and 1.00(0.25,3.50)h;t1/2 were(36.1±9.2)and(36.0±8.2)h;AUC0_72h were(27 402.40±4 752.00)and(26 933.90±4 085.80)h·ng·mL-1.The fed condition Cmax were(701.62±120.67)and(718.95±94.81)ng·mL-1;tmax were 4.00(1.00,5.00)and 4.00(0.50,5.00)h;t1/2 were(44.2±12.4)and(44.0±12.0)h;AUC0-72h were(30 253.20±7 018.00)and(30 324.60±6 147.70)h·ng·mL-1.The 90％confidence intervals of the geometric mean ratios of Cmax and AUC0-72 hfor the test preparation and reference preparation were all between 80.00％and 125.00％under fasting and fed conditions.Conclusion Two kinds of lamotrigine tablets are bioequivalent,and have similar safety in Chinese healthy male and female subjects under fasting and fed conditions.

Objective To explore the molecular mechanism of Gualou Guizhi decoction which regulates the interferon regulator factor 5(IRF5)signaling pathway to inhibit M1 type microglia activation and reduce the inflammatory response to protect damaged nerve cells.Methods Microglia(BV2)cells were randomly divided into BV2-control,BV2-model,BV2-experimental-L,-M,-H groups.The BV2-control group was given routine culture;the BV2-model group used 100 ng·mL-1 lipopolysaccharide(LPS)to stimulate BV2 which establish an inflammatory model;the BV2-experimental-L,-M,-H groups were cultured in 50,100,200 μg·mL-1 GLGZD and 100 ng·mL-1 LPS.The HT22 cells were divided into the HT-22-blank group,HT-22-model group,HT-22-control group and HT-22 experimental group.HT-22-blank group were conventional culture;HT-22-model group were oxygen glucose deprivation was performed for 2 h,then the complete medium was replaced for 24 h;HT-22-control group were after 2 h of oxygen glucose deprivation,the 100 ng·mL-1 LPS conditioned medium was replaced and incubated for 24 h;HT-22-experimental group were after 2 h of oxygen glucose deprivation,the 200 μg·mL-1 GLGZD conditioned medium was added for 24 h.Interleukin-12(IL-12)and IL-23 were detected by enzyme-linked immunosorbent assay(ELISA);the protein of IRF5,cluster differentiation 16(CD1 6)and MHC class Ⅱ(MHC-Ⅱ)was detected by Western blot;the expression of the synaptic marker protein class Ⅲ β-Tubulin(Tuj-1)was observed by immunofluorescence.Results IL-12 contents in the BV2-control,BV2-model and BV2-experimental-L,-M,-H groups were(2.62±1.02),(10.67±3.22),(6.87±1.61),(3.96±1.22)and(3.36±1.04)pg·mL-1;IL-23 contents were(20.40±2.04),(77.08±3.25),(76.28±3.75),(63.96±4.94)and(54.48±3.34)pg·mL-1;relative expression levels of IRF5 protein were 0.80±0.41,2.22±0.69,1.11±0.11,0.92±0.39 and 0.65±0.29;relative expression levels of CD16 protein were 0.69±0.45,1.91±0.52,1.42±0.22,1.04±0.15 and 0.67±0.30;relative expression levels of MHC-Ⅱ protein were 0.89±0.27,1.96±0.19,1.34±0.38,1.15±0.19 and 0.68±0.24.BV2-experimental-M,-H groups were compared with the BV2-model group,the differences were statistically significant(all P＜0.05).The Tuj-1 protein expression levels were 28.85±6.69,14.44±1.98,7.75±1.12 and 20.05±3.54,determined in the HT22-blank,HT22-model,HT22-control and HT22-experimental groups.The HT22-experimental group was compared with the HT22-control group,the difference was statistically significant(P＜0.05).Conclusion GLGZD may reduces the activation of microglia M1 phenotype through IRF5 signaling pathway,and then inhibits inflammatory response to protect damaged nerve cells.

Objective To explore characteristics of clinical parameters and cytokines in patients with drug-induced liver injury(DILI)caused by different drugs and their correlation with clinical indicators. Method The study was conducted on patients who were up to Review of Uncertainties in Confidence Assessment for Medical Tests(RUCAM)scoring criteria and clinically diagnosed with DILI.Based on Chinese herbal medicine,cardiovascular drugs,non-steroidal anti-inflammatory drugs(NSAIDs),anti-infective drugs,and other drugs,patients were divided into five groups.Cytokines were measured by Luminex technology.Baseline characteristics of clinical biochemical indicators and cytokines in DILI patients and their correlation were analyzed. Results 73 patients were enrolled.Age among five groups was statistically different(P=0.032).Alanine aminotransferase(ALT)(P=0.033)and aspartate aminotransferase(AST)(P=0.007)in NSAIDs group were higher than those in chinese herbal medicine group.Interleukin-6(IL-6)and tumor necrosis factor alpha(TNF-α)in patients with Chinese herbal medicine(IL-6:P<0.001;TNF-α:P<0.001)and cardiovascular medicine(IL-6:P=0.020;TNF-α:P=0.001)were lower than those in NSAIDs group.There was a positive correlation between ALT(r=0.697,P=0.025),AST(r=0.721,P=0.019),and IL-6 in NSAIDs group. Conclusion Older age may be more prone to DILI.Patients with NSAIDs have more severe liver damage in early stages of DILI,TNF-α and IL-6 may partake the inflammatory process of DILI.

This article reported two cases of axillary artery thrombosis in extremely low/very low birth weight infants following the placement of a local arterial catheter, who hospitalized in Shengjing Hospital of China Medical Universityin in April 2023 and August 2022, respectively. Case 1: Before surgery for necrotizing enterocolitis, an arterial catheter was placed in the left axilla of the infant. On the same day, the infant developed cyanosis of the left upper limb and weakened radial artery pulse. Ultrasound examination confirmed the presence of left axillary artery thrombosis. Despite subcutaneous injection of low molecular weight heparin (LMWH) and plasma infusion, there was no improvement in blood circulation. The infant also exhibited reduced movement in the left upper limb and loss of radial artery pulse. Thrombolytic therapy with recombinant tissue-type plasminogen activator was administered. Six hours after the treatment, the radial artery pulse became palpable. Thrombolysis was then terminated, and anticoagulation with LMWH was supplied for two weeks. At one year and eight months of age, the infant had a weaker left-hand grip strength compared to the right, but the overall functionality was largely preserved. Case 2: The infant developed late-onset sepsis at 17 days old and had an arterial catheter placed in the axilla. Pale left upper limb was observed in the following day, and the brachial and radial artery pulses were absent. Vascular ultrasound indicated the presence of left axillary artery thrombosis. Anticoagulation therapy with subcutaneous injection of LMWH was provided, along with thrombolysis using urokinase. On the sixth day after thrombolysis, an ultrasound examination showed no thrombus-like echoes. At one year and eight months of age, the development and movement of the affected upper limb became normal.

Patients with severe trauma require an extremely timely treatment and transfusion plays an irreplaceable role in the emergency treatment of such patients. An increasing number of evidence-based medicinal evidences and clinical practices suggest that patients with severe traumatic bleeding benefit from early transfusion of low-titer group O whole blood or hemostatic resuscitation with red blood cells, plasma and platelet of a balanced ratio. However, the current domestic mode of blood supply cannot fully meet the requirements of timely and effective blood transfusion for emergency treatment of patients with severe trauma in clinical practice. In order to solve the key problems in blood supply and blood transfusion strategies for emergency treatment of severe trauma, Branch of Clinical Transfusion Medicine of Chinese Medical Association, Group for Trauma Emergency Care and Multiple Injuries of Trauma Branch of Chinese Medical Association, Young Scholar Group of Disaster Medicine Branch of Chinese Medical Association organized domestic experts of blood transfusion medicine and trauma treatment to jointly formulate Chinese expert consensus on blood support mode and blood transfusion strategies for emergency treatment of severe trauma patients ( version 2024). Based on the evidence-based medical evidence and Delphi method of expert consultation and voting, 10 recommendations were put forward from two aspects of blood support mode and transfusion strategies, aiming to provide a reference for transfusion resuscitation in the emergency treatment of severe trauma and further improve the success rate of treatment of patients with severe trauma.

Objective To investigate the 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]

Immmunosuppressants are mainly used to reduce rejection after solid organ transplantation,so as to improve the success rate of organ transplantation.However,long-term use of immunosuppressants can also serious-ly impair the immune function of patients,thereby increasing the risk of viral infection and postoperative complica-tions,leading to transplant failure.Therefore,patients need to use both immunosuppressants and antiviral agents.If some immunosuppressants with antiviral effects are found,the patient's burden of taking medicines will be greatly reduced.Currently,the immunosuppressants with antiviral effect have been focused by researchers.The gradual re-vealing of the antiviral mechanism of these immunosuppressants will help to optimize the treatment plan of postope-rative rehabilitation of organ transplant recipients.Based on the mechanism of rejection of transplanted organ,this paper systematically describes the types of viruses which closely related to infection of organ transplant patients and the molecular mechanism of some immunosuppressants in antiviral aspects,which further provides a new idea for clinical prevention and treatment of viral infection due to organ transplantation.