ObjectiveTo systematically elucidate the accumulation characteristics of secondary metabolites in the stems and leaves of Panax ginseng with different stem colors. MethodsUltra-high-performance liquid chromatography-triple quadrupole-tandem mass spectrometry （UHPLC-QqQ-MS） was employed to determine the of 22 ginsenosides in the stems and leaves of 2- to 5-year-old P. ginseng plants with green and purple stems. Principal component analysis （PCA）， orthogonal partial least squares-discriminant analysis （OPLS-DA）， and one-way analysis of variance （ANOVA） were performed to explore the distribution patterns of ginsenosides from three dimensions： tissue distribution， growth duration， and stem color. Results① Tissue distribution： Leaves served as the primary organ for ginsenoside accumulation， exhibiting significantly higher total ginsenoside content than stems， which indicated distinct tissue-specific distribution of ginsenosides. ② Growth duration： Ginsenoside levels in stems generally peaked in the 2-year-old plants before stabilizing， while those in leaves displayed a declining-rebounding pattern， indicating that the 2-year-old plants （harvest stage） was a critical time point for the resurgence of leaf ginsenosides. ③ Stem color： A stage-specific correlation was observed between stem color and ginsenoside accumulation. In stems， the early-growth stage （2-year-old） of purple-stemmed plants exhibited higher content of specific ginsenosides （e.g.， ginsenoside Rk₁ and notoginsenoside R₁）， which may be associated with its stronger early-stage stress resistance. In leaves， the content of core ginsenosides （e.g.， ginsenosides Re and Rd） in 5-year-old plants with green stems showed a surpassing trend， demonstrating higher potential of resource development. ConclusionThe accumulation of ginsenosides in P. ginseng stems and leaves is multidimensionally regulated by tissue type， growth duration， and stem color phenotypes. Purple-stemmed plants exhibit early-stage specific ginsenoside accumulation and stress resistance potential， whereas green-stemmed plants are more advantageous for core leaf ginsenoside development at the harvest stage. The findings confirm that aboveground stem color can serve as a biomarker for directed breeding and efficient resource utilization of P. ginseng.

ObjectiveTo systematically elucidate the accumulation characteristics of secondary metabolites in the stems and leaves of Panax ginseng with different stem colors. MethodsUltra-high-performance liquid chromatography-triple quadrupole-tandem mass spectrometry （UHPLC-QqQ-MS） was employed to determine the of 22 ginsenosides in the stems and leaves of 2- to 5-year-old P. ginseng plants with green and purple stems. Principal component analysis （PCA）， orthogonal partial least squares-discriminant analysis （OPLS-DA）， and one-way analysis of variance （ANOVA） were performed to explore the distribution patterns of ginsenosides from three dimensions： tissue distribution， growth duration， and stem color. Results① Tissue distribution： Leaves served as the primary organ for ginsenoside accumulation， exhibiting significantly higher total ginsenoside content than stems， which indicated distinct tissue-specific distribution of ginsenosides. ② Growth duration： Ginsenoside levels in stems generally peaked in the 2-year-old plants before stabilizing， while those in leaves displayed a declining-rebounding pattern， indicating that the 2-year-old plants （harvest stage） was a critical time point for the resurgence of leaf ginsenosides. ③ Stem color： A stage-specific correlation was observed between stem color and ginsenoside accumulation. In stems， the early-growth stage （2-year-old） of purple-stemmed plants exhibited higher content of specific ginsenosides （e.g.， ginsenoside Rk₁ and notoginsenoside R₁）， which may be associated with its stronger early-stage stress resistance. In leaves， the content of core ginsenosides （e.g.， ginsenosides Re and Rd） in 5-year-old plants with green stems showed a surpassing trend， demonstrating higher potential of resource development. ConclusionThe accumulation of ginsenosides in P. ginseng stems and leaves is multidimensionally regulated by tissue type， growth duration， and stem color phenotypes. Purple-stemmed plants exhibit early-stage specific ginsenoside accumulation and stress resistance potential， whereas green-stemmed plants are more advantageous for core leaf ginsenoside development at the harvest stage. The findings confirm that aboveground stem color can serve as a biomarker for directed breeding and efficient resource utilization of P. ginseng.

OBJECTIVE To investigate the distribution and drug resistance of the pathogens isolated from sterile body fluids in a hospital so as to provide reference for clinical treatment of the infections.METHODS The sterile body fluids specimens that were cultured positive for pathogens were retrospectively collected from a three-A hos-pital of Jiangxi Province between 2016 and 2023.The distribution and drug resistance of the isolated pathogens were observed.RESULTS Totally 16,658 strains of pathogens were isolated from the sterile body fluid speci-mens in 2016-2023,among which gram-negative bacteria accounted for 51.74％.The species of bacteria that ranked the top 5 places were as follows:Escherichia coli,Klebsiella pneumoniae,Staphylococcus epidermidis,Staphylococcus hominis,and Staphylococcus aureus.The isolation rates of methicillin-resistant Staphylococcus aureus and methicillin-resistant coagulase-negative Staphylococcus were 28.32％and 74.94％,respectively;the strains maintained high sensitivity to linezolid and vancomycin,with the drug resistance rates no more than 2.50％.The drug resistance rates of Enterococcus faecium and Enterococcus faecalis to linezolid and vancomycin were always less than 4.20％.Among the species of Enterobacter,the drug resistance rates of the E.coli strains to meropenem declined from 17.65％to 5.94％;conversely,the drug resistance rate of the K.pneumoniae strains to carbapenems reached high up to 54.36％,showing an upward trend on the whole.Among the non-fermenting gram-negative bacteria,the drug resistance rate of the A.baumannii strains to carbapenems remained high(about 80.00％);while the drug resistance rates of the P.aeruginosa strains to meropenem dropped from 60.71％down to 24.32％.CONCLUSIONS The gram-negative bacteria are dominant among the pathogens isolated from the ster-ile body fluids in the hospital between 2016 and 2023.Although some major species of drug-resistant pathogens are effectively under control,the pathogens isolated from the sterile body fluid specimens maintain varying degree of drug resistance to various types of antibiotics.

Purpose To measure the spatial resolution in MRI quality control testing automatically based on the American College of Radiology(ACR)phantom using the support vector machine(SVM)method,and the feasibility,accuracy and measurement speed of this method are explored.Materials and Methods Quality control tests were performed using eight MRI devices at Beijing Friendship Hospital of Capital Medical University.A retrospective study was conducted on 71 MRI quality control test images collected based on ACR phantoms between 2017 and 2019.The images were preprocessed by binarization,extraction region of interest and so on.An SVM-based classification model was constructed for analyzing the spatial resolution of dot arrays in row and column directions.The dataset was randomly split into a training set and a test set.The generalization performance of the classification model in this study was evaluated through accuracy,precision,recall and F1 score on the test set.Comparing the results of spatial resolution measurements obtained by both manual and automatic method,we demonstrated the feasibility and accuracy of the method.Additionally,the time taken for the automatic spatial resolution measurement was recorded.Results In this study,the proposed method of automatically measuring the spatial resolution of ACR phantom test images using SVM was feasible,high accuracy and short time.In classification performance test,the accuracy of the spatial resolution of the row directional latices was 95%,the precision was 100%.The accuracy of the spatial resolution of the column directional latices was 97%,the precision was 100%.Among the test cases,the results of automatic measurements matched those of manual measurements in 13 out of 14 cases.On average,automatic spatial resolution measurement took 0.158 seconds per case.Conclusion This study achieves automatic measurement of spatial resolution in MRI quality control based on the ACR phantom using SVM method.The method demonstrates high accuracy and fast measurement speeds,holding significant implications for future rapid MRI quality control stability testing.

OBJECTIVE To investigate the distribution and drug resistance of the pathogens isolated from sterile body fluids in a hospital so as to provide reference for clinical treatment of the infections.METHODS The sterile body fluids specimens that were cultured positive for pathogens were retrospectively collected from a three-A hos-pital of Jiangxi Province between 2016 and 2023.The distribution and drug resistance of the isolated pathogens were observed.RESULTS Totally 16,658 strains of pathogens were isolated from the sterile body fluid speci-mens in 2016-2023,among which gram-negative bacteria accounted for 51.74％.The species of bacteria that ranked the top 5 places were as follows:Escherichia coli,Klebsiella pneumoniae,Staphylococcus epidermidis,Staphylococcus hominis,and Staphylococcus aureus.The isolation rates of methicillin-resistant Staphylococcus aureus and methicillin-resistant coagulase-negative Staphylococcus were 28.32％and 74.94％,respectively;the strains maintained high sensitivity to linezolid and vancomycin,with the drug resistance rates no more than 2.50％.The drug resistance rates of Enterococcus faecium and Enterococcus faecalis to linezolid and vancomycin were always less than 4.20％.Among the species of Enterobacter,the drug resistance rates of the E.coli strains to meropenem declined from 17.65％to 5.94％;conversely,the drug resistance rate of the K.pneumoniae strains to carbapenems reached high up to 54.36％,showing an upward trend on the whole.Among the non-fermenting gram-negative bacteria,the drug resistance rate of the A.baumannii strains to carbapenems remained high(about 80.00％);while the drug resistance rates of the P.aeruginosa strains to meropenem dropped from 60.71％down to 24.32％.CONCLUSIONS The gram-negative bacteria are dominant among the pathogens isolated from the ster-ile body fluids in the hospital between 2016 and 2023.Although some major species of drug-resistant pathogens are effectively under control,the pathogens isolated from the sterile body fluid specimens maintain varying degree of drug resistance to various types of antibiotics.

Creutzfeldt-Jakob disease(CJD)is a rapidly progressive and fatal neurodegenerative disorder caused by prions,with certain infectivity and iatrogenic transmission risks.With the rapid progress and application of new dia-gnostic biomarkers and detection methods,as well as the construction and improvement of surveillance and reporting systems,the detection of CJD in patients domestically and internationally has shown an increasing trend year by year.Due to its long incubation period and heterogeneity of early symptoms,early identification and diagnosis of the disease is difficult,increasing the risk of transmission within medical institutions.Currently,there is a lack of con-sensus on the infection prevention and control of CJD.In order to timely identify and diagnose CJD as well as effec-tively block its transmission in medical institutions,this consensus summarizes 15 clinical concerns and formulates 24 specific recommendations based on the latest domestic and international research findings and clinical evidence,as well as combines with clinical practice,aiming to standardize healthcare-associated infection prevention and control measures for CJD and reduce its transmission risk in medical institutions.

In June 2018,sows at a pig farm in Jiamusi,Heilongjiang Province,suffered a large num-ber of miscarriages,and subsequently weaned piglets at the farm began to show persistent high fe-ver symptoms at around 35 days of age,with some pigs having a fever of more than 41.5 ℃.In or-der to determine the cause of this outbreak,63 clinical samples from this farm were tested.The re-sults showed that 60 out of 63 samples were positive for the porcine reproductive and respiratory syndrome virus(PRRSV)antigen.Subsequently,PRRSV antigen-positive plasmid was transfected into African green monkey embryonic kidney cells(Marc-145),and after three generations of blind transmission,indirect immunofluorescence assay(IFA)was performed.The results showed that one PRRSV strain,named HLJ38,was successfully isolated.Then the whole genome of HLJ38 strain was sequenced and then analyzed in detail by bioinformatics software.Sequence analysis showed that there were three deletions of 131 amino acids(323-433 aa,483 aa and 504-522 aa)in the derived sequence of Nsp2 gene of HLJ38 strain,which was consistent with the molecular ge-netic marker of NADC30 PRRSV.The phylogenetic tree analysis showed that HLJ38 and NADC30 PRRSV in GenBank belong to lineage 1 subgroup,and the nucleotide homology of HLJ38 and NADC30 PRRSV in GenBank was only 85.2％and 84.6％.Recombinant analysis showed that HLJ38 was a recombinant NADC30-like PRRSV,and the recombinant gene fragments were de-rived from multiple strains,among which the fragment of 1-201 nt was provided by VR2332 strain and fragment of 6 641-8 061 nt derived from the HP-PRRSV strain.In summary,the re-sults showed that the outbreak in this pig farm may be caused by the recombination of PRRSV strains among different lineages,and the recombinant circulating strains not only have certain pathogenicity but also suggest that the existing commercial vaccines provide limited cross-protec-tion against them.Recombination between different lineages increases the genetic diversity of PRRSV and aggravates the difficulty of prevention and control of PRRS in pig farms.Therefore,it is necessary to continuously monitor the epidemic dynamics of PRRSV in pig farms and take effec-tive measures in time to curb the spread of PRRS.

Objective To compare the ability of single-phase,dual-phase,and triphasic models in forecasting postoperative pancreatic fistula(POPF)after pancreaticoduodenectomy(PD)using radiomics based on triphasic enhanced CT.Methods A total of 181 patients who underwent multi-phase enhanced CT prior to PD were retrospectively selected,and the collection phase included non-contrast,arterial phase(AP),and equilibrium phase(EP).3D Slicer software was utilized to segment the region of interest(ROI)for the postoperative pancreatic remnant on each phase.Radiomics feature extraction was performed using R software,followed by feature selection through least absolute shrinkage and selection operator(LASSO)regression with five-fold cross-validation to prevent model overfitting.The effective features selected were combined in a weighted linear manner to obtain a Radiomics score(Radscore).The patients were divided into training set and test set in a 7︰3 ratio.Logistic regression was employed to construct seven POPF prediction models(three single-phase,three dual-phase,and one triphasic models)based on different phase combinations.The diagnostic performance of the models was evaluated using the area under the curve(AUC)of receiver operating characteristic(ROC)curve,accuracy(ACC),sensitivity(SEN),and specificity(SPE).The DeLong test was applied to compare the differences in AUC among different models.Results After LASSO regression,24 effective features associated with POPF were selected from different phases.In the test set,the triphasic model exhibited the highest AUC and ACC(AUC=0.76,ACC=0.808).The calibration curve demonstrated the strongest agreement between the estimated probabilities and observed probabilities for the triphasic model.The decision curve analysis(DCA)curve indicated that the triphasic model had the largest threshold range with a higher net benefit.Conclusion Compared with single-phase and dual-phase models,the triphasic model based on enhanced CT provides better prediction of POPF after PD,aiding clinical decision-making and improve prognosis.

Objective:To establish a method for the rapid detection of varicella-zoster virus (VZV) by recombinase-aid amplification (RAA) combined with Clustered regularly interspaced short palindromic repeats (CRISPR)/Cas12a system.Methods:Clinical samples of suspected herpes zoster in Shandong province and Shanghai from 2023 to 2024 were collected, nucleic acids of positive samples were extracted, RAA-specific primers and crRNA (CRISPR RNA, crRNA) were designed for the conserved region of VZV, and the fluorescence intensity generated by Cas12a non-specific cleavage of single-stranded fluorescent probes was used to screen highly sensitive crRNAs and optimize the concentrations of crRNA, Cas12a and ssDNA probes. The sensitivity and reproducibility of the RAA-CRISPR/Cas12a detection method were evaluated by using synthesized plasmids and clinical samples, and the specificity of the method was evaluated by using other viral nucleic acids. The method was used to detect clinical samples by using the method and quantitative real-time PCR (qPCR) method, and the detection rate and consistency of the two method were compared.Results:The highly sensitive crRNA-4 was screened from the four crRNAs designed, and a VZV detection method for RAA-CRISPR/CAS12a based on fluorescence intensity measurement was established, which could be detected at 37℃ in 45 min, and the sensitivity of the detection could reach 10 copies/μL, a minimum clinical sample with a Ct value of 38.980 can be detected. It has high specificity and no cross-reactivity with Adenovirus 7, Herpes simplex virus type I, Herpes simplex virus type II, Coxsackieviruses A16, Cytomegalovirus, Epstein-Barr virus, Measles virus, Mumps virus, Enterovirus 71, Japanese encephalitis virus genotype 5. It has good stability, and can be successfully detected in low, medium and high concentrations of viral positive plasmids with good consistency. The detection rate of the clinically positive samples was 100%, which was completely consistent with the qPCR test result.Conclusions:RAA isothermal amplification technology combined with CRISPR-CAS12a technology was used to establish an accurate method for the detection of VZV virus, which was highly sensitive, specific, and had low requirements for experimental conditions, and could be completed within 45 min, which could provide strong technical support for the early detection of VZV.

Objective To investigate the application of the"integration of four dimensions(mainline teaching-on-line course-medical case-mind map)"teaching mode in the undergraduate compulsory teaching course"Health-care-associated Infection Control",and provide reference for further improving the design of undergraduate compul-sory course on infection control.Methods A questionnaire survey on undergraduate students' satisfaction for com-pulsory course"Healthcare-associated Infection Control"was conducted using KANO model.A total of 4 dimen-sions and 21 quality indicators were set up.KANO attribute classification,satisfaction degree,and importance coef-ficients etc.were analyzed,and curriculum design was optimized.Results The overall questionnaire reliability Cronbach's a coefficient was 0.915,and the validity analysis Kaiser-Meyer-Olkin(KMO)measure of sampling adequacy value was 0.867.Among the 21 quality indicators,12 were charismatic attributes,which accounted for the largest proportion(57.14％)of the total indicators.Most quality indicators received high student satisfaction ratings.The indicators with the highest satisfaction coefficients were"playing teaching videos in class"(4.73),along with"in-tegrating typical healthcare-associated infection cases into the curriculum for relevant teaching""maintaining a relax-ed and pleasant teaching atmosphere",and"humorous and witty teaching style of the teacher"(all scoring 4.71).Four important but currently with low satisfaction indicators were"combining course content with utilitarian exam preparation""adopting a completely offline teaching format""adopting relatively strict assessment methods",and"reflecting differentiation based on difficulty coefficient in final assessment".Conclusion This course has achieved certain efficacy in undergraduate compulsory education,but there is still room for improvement in the setting of cur-riculum assessment methods.In the future,the course system should be integrated,the assessment mode of combi-ning theory and practice should be optimized,and course improvement and innovation should be promoted.