In recent years, the bacteriophage Φ29 (Phi29) DNA polymerase has garnered increasing attention due to its high-fidelity amplification capacity at constant temperatures. To advance the industrial application of this type of isothermal polymerases, this study mined and characterized new enzymes from the microbial metagenome based on the known Phi29 DNA polymerase sequence. The results revealed that a new enzyme, Php29 DNA polymerase, was identified in the microbial metagenome with plants as the hosts. This enzyme exhibited higher strand displacement activity, with a 59.5% similarity to bacteriophage Φ29. Experimental validation demonstrated that the enzyme had 3'→5' exonuclease activity, and its amplification products can serve as substrates for further catalytic reactions. The discovery and validation of Php29 DNA polymerase gives insights into the future industrial application of isothermal polymerases.
DNA-Directed DNA Polymerase/metabolism* ; Bacillus Phages/genetics* ; Metagenome

ObjectiveTo analyze the scores of the second-tier assessment on theory of competency of Traditional Chinese Medicine （TCM） physicians based on cognitive diagnostic model， and to provide a reference for cognitive diagnostic studies of large-scale medical examinations. MethodsCognitive diagnostic analyses were conducted by selecting the responses of 16，310 candidates who took the theory examination of the second-tier assessment on the competency of TCM physicians in 2023. The degree of fit between the topological deterministic input noise and gate model （G-DINA model） and the examination data was examined； item parameter analysis and reliability analysis were conducted under the cognitive diagnostic framework； the candidates' mastery of cognitive attributes was comprehensively analysed at different levels. ResultsThe mean score of 16，310 candidates in this study was （189.76 ± 40.86）， and a total of 9，994 candidates passed this examination， with a pass rate of 61.28 %. The total number of questions in the examination was 300， and among the five modules， the frequency of assessment of TCM fundamentals was the highest （132 questions， 44%）， followed by TCM clinic （87 questions， 29%）， Western medicine fundamentals （60 questions， 20%）， and TCM classics （12 questions， 4%） and medical humanities （9 questions， 3%） was less. The results of the model fit index showed that the area under the curve （AUC） of the G-DINA model was 0.98， indicating that the model fit the study data excellently. The results of item parameter analysis showed that all the discriminations of the cognitive diagnostic model for the 300 test questions were greater than 0， with an average discrimination of 0.25， and the overall performance of the question discriminations was good. The results of the reliability analysis showed that the test level classification accuracy was 0.75， and the attribute level classification accuracy was 0.83 to 0.99， indicating that the G-DINA model has high attribute classification accuracy. The results of the cognitive diagnostic analyses showed that the proportion of candidates who had passed the exam was higher for the cognitive attributes of each module compared to those who had not passed the exam. ConclusionThe analysis of large-scale TCM examinations based on cognitive diagnosis can provide support for improving the quality of TCM talent education and cultivation.

Background The threshold limit values (TLVs) established and regularly updated by the American Conference of Governmental Industrial Hygienists (ACGIH) are widely adopted and referenced globally, serving as a crucial reference for China's occupational exposure limits (OELs). It is necessary to track it regularly and compare it with China's OELs. Objective To compare the OELs stipulated in Occupational exposure limits for hazardous agents in the workplace—Part 1: Chemical hazardous agents (GBZ 2.1—2019) and the ACGIH TLVs (2024) and to provide references for subsequent formulation and revision of OELs in China. Methods The OELs specified in GBZ 2.1—2019 and the TLVs issued by ACGIH were used to establish a database using Microsoft Excel 2019 software. Cross verification was conducted through matching Chemical Abstracts Service Registry Numbers (CAS Rn) and both Chinese and English names to ensure accuracy. Then, comparisons and analyses were carried out based on the type of limit values, which were matched as follows: permissible concentration-time weighted average (PC-TWA) with threshold limit value-time weighted average (TLV-TWA), permissible concentration-short term exposure limit (PC-STEL) with threshold limit value-short term exposure limit (TLV-STEL), and maximum allowable concentration (MAC) with threshold limit value-ceiling (TLV-C). Comparisons included types, quantities, and sizes of limits. Results The GBZ 2.1—2019 OELs and the ACGIH TLVs (2024) were generally consistent in terms of types and definitions, but there were differences in the number and size of the limits. In terms of the number of limits, GBZ 2.1—2019 specified 365 OELs for 358 chemical hazardous agents, while ACGIH TLVs (2024) included 316 corresponding limits. Among these, 148 (46.9%) limits were consistent, 38 (12.0%) were basically consistent, and 130 (41.1%) were inconsistent. In terms of the size of the limits, out of the 130 inconsistent limits, 51 OELs were lower than the corresponding TLVs, 67 OELs were higher than the corresponding TLVs, and 12 were under different limit types. For some chemical hazardous agents, their OELs were significantly lower or higher than their TLVs. Conclusion Some of the OELs for chemical hazardous agents specified in GBZ 2.1—2019 are significantly lower or higher than the TLVs. For these chemical hazardous factors, it is recommended to prioritize their inclusion in research projects and to complete the revisions as soon as possible based on the latest scientific evidence.

Hepatocellular carcinoma(HCC)is the most common type of primary liver cancer and the third leading cause of cancer-related deaths,and it is a serious threat to human health and has become a clinical problem that needs to be solved urgently.Extracellular vesicles(EV)are membrane vesicles containing multiple components and play an important role in the development and progression of HCC.This article summarizes the effect of EVs of different origins on HCC and analyzes the mechanism of action of EV on HCC,so as to provide new perspectives for the diagnosis and treatment of HCC.

Objective To explore the prognostic impact and clinical application value of therapeutic plasma exchange(TPE)intervention timing and liver injury periodization in patients with exertional heat stroke(EHS).Methods Data of 127 EHS patients from the First Medical Center of the General Hospital of the People′s Liberation Army from January 2011 to December 2023 were collected,then divided into the death group and the survival group based on therapeutic outcomes and into 5 stages according to the dynamic changes of ALT,AST,TBIL and DBIL.According to propensity score matching analysis,11 patients in the survival group and 12 patients in the death group were included in the statistical analysis,and 20 of them were treated with TPE.The changes in indicators and clinical outcomes before and after TPE were observed,in order to evaluate the impact of intervention timing on prognosis.Results Among the 23 patients,14 had no liver injury or could progress to the repair phase,resulting in 3 deaths(with the mortality rate of 21.43%),while 9 patients failed to pro-gress to the repair phase,resulting in 9 deaths(with the mortality rate of 100%),with significant differences(P＜0.05).The mortality rate of the first TPE intervention before the third stage of liver injury was 23.08%(3/13),while that of interven-tion after reaching or exceeding the third stage was 85.71%(6/7),and the difference was statistically significant(P＜0.05).Conclusion TPE should be executed actively in EHS patients combined with liver injury before the third phase to lock its pathological and physiological processes,thereby improving prognosis and reducing mortality.

Objective To review the occurrence of allergic reactions during therapeutic plasma exchange(TPE)and to explore the risk factors of TPE allergic reactions.Methods The clinical data of 929 patients treated with TPE using plasma components by the Department of Transfusion Medicine in our medical center from 2018 to 2023 were collected.The influen-cing factors of allergic reactions were analyzed by univariate analysis,and the independent risk factors of allergic reactions were analyzed by logistic multivariate regression analysis.Results A total of 4 071 TPEs were performed in 929 patients.A-mong them,198 patients(21.31%)experienced 349 times(8.57%)of allergic reactions,with the incidence of gradeⅠ,Ⅱ and Ⅲ allergic reactions of 16.33%,81.38%and 2.29%,respectively,and no deaths.The univariate analysis showed that the patient′s age,allergy history,diagnosis of immune-related diseases,ICU admission,plasma consumption,total blood volume,maximum blood flow rate and combined use of albumin were related to the occurrence of allergic reactions(P＜0.05).Multivariate regression analysis showed that young patients,a history of allergy,immune-related diseases and non-ICU patients were prone to allergic reactions in TPE,but the treatment options of TPE such as substitute fluid category,plasma consumption and blood flow rate were not related to the occurrence of allergic reactions.Conclusion There are sig-nificant individual differences in the occurrence of allergic reactions for TPE,and young age,history of allergies,immune-related diseases and non-ICU patients are risk factors for allergic reactions in TPE.Identifying patients with risk factors be-fore TPE treatment and giving corresponding preventive measures can reduce the incidence of allergic reactions.

As the continuation of the left ventricle,the left atrium and left ventricle interact and play an important role in the function of the whole heart.At present,there are many techniques to evaluate the atrial structure and function,but the left atrial structure is complex and the myocardium is thin,which brings some challenges to the relevant evaluation.This paper introduces the parameters,precautions and relevant clinical applications in the process of left atrial evaluation from the aspects of myocardial strain and delayed enhancement.

Hypoxia-inducible factor (HIF-1α), a core transcription factor responding to changes in cellular oxygen levels, is closely associated with a wide range of physiological and pathological conditions. However, its differential impacts on vascular cell types and molecular programs modulating human vascular homeostasis and regeneration remain largely elusive. Here, we applied CRISPR/Cas9-mediated gene editing of human embryonic stem cells and directed differentiation to generate HIF-1α-deficient human vascular cells including vascular endothelial cells, vascular smooth muscle cells, and mesenchymal stem cells (MSCs), as a platform for discovering cell type-specific hypoxia-induced response mechanisms. Through comparative molecular profiling across cell types under normoxic and hypoxic conditions, we provide insight into the indispensable role of HIF-1α in the promotion of ischemic vascular regeneration. We found human MSCs to be the vascular cell type most susceptible to HIF-1α deficiency, and that transcriptional inactivation of ANKZF1, an effector of HIF-1α, impaired pro-angiogenic processes. Altogether, our findings deepen the understanding of HIF-1α in human angiogenesis and support further explorations of novel therapeutic strategies of vascular regeneration against ischemic damage.
Humans ; Vascular Endothelial Growth Factor A/metabolism* ; Endothelial Cells/metabolism* ; Transcription Factors/metabolism* ; Gene Expression Regulation ; Hypoxia/metabolism* ; Cell Hypoxia/physiology*

Objective To observe the effect of ultrasound-guided anterior quadratus lumborum block at lateral supra-arcuate ligament(QLB-LSAL)and transversus abdominis plane block(TAPB)on analgesia and recovery quality after laparoscopic partial hepatectomy(LPH).Methods Fifty-eight patients underwent elective LPH were selected and divided into the quadratus lumborum group or the transversus abdominis group randomly,with 29 patients in each group.The quadratus lumborum group received bilateral QLB-LSAL,and the transversus abdominis group received bilateral subcostal TAPB block before surgery.Both groups received 20 mL of 0.33%ropivacaine on each side.All patients used patient-controlled intravenous analgesia(PCIA)postoperatively.The numeric rating scale(NRS)scores for rest and movement were recorded at 2,4,6,12,24 and 48 hours postoperatively,as well as the Quality of Recovery-15(QoR-15)scores at 1 day preoperatively,1 and 3 days postoperatively.The perioperative anesthetic agent consumption,PCIA pressing frequency,remedial analgesia use in 48 h,postoperative nausea and vomiting(PONV)incidence and time of first out-of-bed mobilization were also recorded.Results Compared with the transversus abdominis group,the quadratus lumborum group had lower movement NRS scores at 2,4,6,12,24 and 48 hours postoperatively,and lower rest NRS scores at 2,4,6,12 and 24 hours postoperatively(P＜0.05).The quadratus lumborum group had higher QoR-15 scores at 1 and 3 days postoperatively(P＜0.05).Patients in the quadratus lumborum group had reduced perioperative remifentanil and sufentanil consumption,postoperative 48-hour rescue analgesia use,PCIA pressing frequency,PONV incidence and time of first out-of-bed mobilization(P＜0.05).Conclusion QLB-LSAL block provides superior analgesic effects and recovery quality compared to TAPB block after LPH.

With the continuous development of medical science and the widespread use of antibiotics,the problem of bacterial resistance is increasing,especially the increasing carbapenem-resistant Enterobacteriaceae(CRE)infection,and the high mortality rate,which brings great challenges to clinical treatment.In this paper,the mechanism of drug resistance,existing antibac-terial drugs,and exploratory treatment options for CRE are reviewed,and the research progress in treating CRE infection is dis-cussed to provide more reliable evidence and a theoretical basis for clinical practice.