ObjectiveDonkey hide is the sole legally designated raw material for the preparation of the traditional Chinese medicine Ejiao. The quality stability of donkey hide during preservation directly determines the efficacy and safety of Ejiao. This study focuses on the dynamic succession of microbial communities during the preservation of donkey hides from different origins, aiming to clarify the correlation between microbial biodiversity difference and the degradation profiles of hide collagen and critical biochemical components, thereby providing a theoretical foundation for developing targeted preservation strategies based on microbial regulation. MethodsDonkey hides originating from four different regions were subjected to an accelerated microbial aging assay to simulate the spoilage process. The microbial community succession was analyzed using high-throughput sequencing. Microstructure changes and pore structure characteristics were assessed by scanning electron microscopy and mercury intrusion porosimetry, respectively. Additionally, the content of major components, including lipids, proteins, and sugars were determined by biochemical methods. ResultsAfter 96 h of aging, the collagen fiber structure in Africa donkey hides (ADH) exhibited significant degradation and collapse, followed by Xinjiang donkey hides (XDH). Instead, the microstructure of Dong’e black donkey hides (DDH) and Peru donkey hides (PDH) remained relatively intact. The porosities of DDH, XDH, PDH, and ADH increased from 27.9%, 15.7%, 30.3%, and 46.2% to 36.5%, 52.6%, 42.8%, and 57.7%, respectively, during the aging process, which suggested that the originally compact fiber structure was disrupted by microbial aging. Fourier transform infrared spectrometer analysis revealed the amide bands in XDH exhibited relatively weak intensity, and no collagen amide I band was observed in ADH. Meanwhile, the lipid and protein contents decreased in all four types of donkey hides, indicating that these components served as the primary nutrient sources for the growth of microorganism. Notably, the most severe collagen degradation was observed in XDH and ADH. A substantial increase was detected in the total soluble sugar in PDH aging solution and hydroxyproline in the ADH aging solution, respectively. These results indicated that donkey hides exhibit distinct patterns of structural degradation and nutrient utilization. Furthermore, the viable cells number of donkey hides increased sharply after 48 h of aging. Metagenomic analysis revealed that the relative abundance of Euryarchaeota in ADH, PDH and XDH declining from initial 93.19%, 97.73% and 30.08% to 0.79%, 1.43% and 0.02% after 96 h, respectively. Conversely, a significantly increase was observed in the abundance of Bacillota, with a marked increase in ADH, peaking at 92.75%. Additionally, the abundance of Pseudomonadota in PDH increased from 0.10% to 87.84%, suggesting that Bacillota and Pseudomonadota may be key factors exacerbating donkey hide spoilage. Unlike the other three types of donkey hides, the dominant bacterial phylum in DDH shifted from Pseudomonadota to Bacteroidota, characterized by a substantial abundance increase of Bacteroidota from 0.13% to 44.22%. ConclusionRegional variation in origin significantly influence the microbial aging of donkey hides, leading to distinct patterns of structural deterioration and differential nutrient utilization. Therefore, implementing origin-specific preservation strategies, through the precisely controlling environmental factors to suppress harmful phyla such as Bacillota and Pseudomonadota, is crucial for enhancing the storage quality of donkey hides.

Objective This study conducted molecular biological identification of the viruses carried by Culex pipiens pallens specimens collected in Shunyi District, Beijing in 2023, and observed the changes in the infection rate of the viruses carried by Cx. pipiens pallens at different collection times. Methods Cx. pipiens pallens were collected using carbon dioxide mosquito traps. The mosquito samples were ground in batches and analyzed by molecular biology technologies. The virus infection rate at different collection times was analyzed statistically. Results 17 strains of Culex pipiens pallens densovirus(CppDNV)were identified from Cx. pipiens pallens samples collected in Shunyi District, Beijing, in 2023. The nucleotide sequence analysis of the virus genome coding region showed that CppDNV was a single-stranded DNA virus with a total length of 3 335 nt, encoding 2 non-structural proteins(NS1, NS2)and 1 capsid protein(VP). The nucleotide(amino acid)sequence lengths of the three proteins were 2 376 nt(791 aa),1 092 nt(363 aa)and 1 071 nt(356 aa), respectively. Phylogenetic analysis showed that CppDNV was located in genus Brevihamaparvovirus. Statistical analysis showed no significant difference in infection rates across collection times(χ2=4.429, P=0.194). Conclusions CppDNV was identified in Cx. pipiens pallens in Beijing, and it was stably maintained in this natural population.

Objective To analyze the predictive value of patient-reported outcomes(PRO)com-bined with hematological indicators for moderate-to-severe endoscopic activity in patients with ulcera-tive colitis(UC).Methods Clinical data of UC patients were retrospectively collected,including PRO,hematological parameters and endoscopic findings.Based on the Mayo endoscopic score,pa-tients were divided into remission and mild activity group(＜2 points)and moderate-to-severe activity group(≥ 2 points).Independent influencing factors for moderate-to-severe endoscopic activity were screened through multivariate Logistic regression analysis,and a binary Logistic regression model was constructed.The receiver operating characteristic(ROC)curve was used to evaluate the discriminato-ry ability of the predictive model.The calibration of the model was assessed using calibration curves and the Spiegelhalter Z-test,and the model's performance was further validated in an external valida-tion cohort.Results Rectal bleeding(RB),C-reactive protein/albumin(CAR)and erythrocyte sed-imentation rate(ESR)were independent influencing factors for moderate-to-severe endoscopic activity(P＜0.05).The area under the curve(AUC)of the nomogram predictive model constructed based on the logistic regression analysis results was 0.848(95％CI,0.798 to 0.900),with sensitivity of 76.6％and specificity of 79.6％.In the external validation cohort,the model's AUC was 0.778(95％CI,0.699 to 0.857),and there was no statistically significant difference compared with the AUC of the training cohort model(P＞0.05).In both the training and validation cohorts,the Spiegelhalter Z-test results indicated that the model had good goodness-of-fit(P＞0.05).Conclu-sion RB,CAR and ESR are independent influencing factors for moderate-to-severe endoscopic ac-tivity in UC patients.The combination of RB,CAR and ESR has high predictive value for moderate-to-severe endoscopic activity in UC patients,with good discriminatory and calibration abilities.

AIM To study the chemical constituents from the sticks and leaves of Croton cascarilloides Raeusch.and their biological activities.METHODS The 95％ethanol extract from the sticks and leaves of C.cascarilloides was isolated and purified by MCI,silica gel,Sephadex LH-20 and semi-preparative HPLC,then the structures of obtained compounds were identified by physicochemical properties and spectral data.LPS-induced NO RAW264.7 cell model induced by LPS was used to evaluate its anti-inflammatory activity in vitro.GES-1 injury model induced by taurocholic acid was used to screen the gastric mucosal protection activity.RESULTS Fourteen compounds were isolated and identified as bullatantriol(1),(-)-boscialin(2),(+)-dehydrovomifoliol(3),3-(hydroxylacetyl)-indole(4),pinoresinol(5),3,7-dimethyl-octa-1,7-diene-3,6-ol(6),(+)-syringaresinol(7),curcasinlignan B(8),cleomiscosin C(9),cleomiscosinD(10),2,6-dimethyl-octa-1,7-dien-3,6-diol(11),vanillin(12),vanillic acid(13),methyl vanillate(14).Compound 4 had certain anti-inflammatory activity,with IC50 values of 73.62 μmol/L.The protective rates of 25 μmol/L compounds 1-4,6,9-12 and 14 on gastric mucosal epithelial cells were 30.07％,34.18％,23.91％,30.92％,17.51％,19.69％,31.76％,22.46％,30.56％and 14.49％,respectively.CONCLUSION Compounds 1-14 are isolated from this plant for the first time.Compound 4 shows anti-inflammatory activity,1-4,6,9-12 and 14 show different degrees of gastric mucosal epithelial cell protective activity.

Objective To construct a symptom network in patients with acute type A aortic dissection(ATAAD),so as to provide theoretical basis for the screening of dissection ATAAD during emergency pre-screening triage.Methods There were 433 patients diagnosed with ATAAD during 2019 to 2023 in an emergency department of a tertiary hospital in Wuhan.Their basic information and medical records were reviewed by self-designed data questionnaire.UCINET6.0 software was used to construct a symptom network,analyze the centrality index and determine the core symptoms.Symptom distribution of patients with positive and negative blood pressure in extremities was analyzed in the further.Results The most common symptoms in patients with type A aortic dissection were chest pain(77.37％),back pain(42.96％),and sweating(29.79％).In the symptom network,chest pain had the highest degree(rs=659).The closeness of chest pain,chest tightness,shortness of breath,back pain,nausea and vomiting,limb numbness and fatigue were same(rc=93.33).Fatigue has the highest betweenness(rb=13.69).Patients with positive limbs blood pressure mainly reported chest pain(70.17％),back pain(44.96％),and nausea and vomiting(19.33％),while those with negative limb blood pressure mainly reported chest pain(63.64％),back pain(63.64％),and orosphyalgia(39.40％).Orosphyalgia had the highest degree(rs=20).Conclusion The symptoms of ATAAD are complex and varied in patients.During triage,nurses should measure the limb blood pressure when patients complained chest pain alone or when combined with other hypoperfusion symptoms,such as back pain,chest tightness,sweating,near-death sensation,and shortness of breath.Aortic dissection cannot be ruled out in patients with negative blood pressure when they had chest pain,back pain or orosphyalgia.

A method was developed for determination of dilauryl thiodipropionate(DLTDP)in fried foods by coupling solid-phase extraction(SPE)pretreatment with reverse-phase liquid chromatography-tandem mass spectrometry(RPLC-MS/MS)detection.Samples were extracted with n-hexane as the solvent,purified using a neutral alumina SPE cartridge,and finally analyzed by RPLC-MS/MS.Quantitative analysis was performed using matrix-matched calibration curves combined with an external standard method under optimal experimental conditions.The results showed that DLTDP exhibited good linearity in the range of 2.0-50.0 μg/L,with a correlation coefficient(R2)≥0.999.The limit of detection(LOD)and the limit of quantification(LOQ)of the method were 0.15 mg/kg and 0.5 mg/kg,respectively.The mean recoveries at three fortification levels(0.5,1.0,and 200 mg/kg)in different samples ranged from 84.8%to 96.8%,with the relative standard deviations(RSDs)all less than 8.0%.The developed method was highly sensitive,accurate and reliable,and easy to operate,making it well suited for the routine quantitative analysis of DLTDP in fried foods.

In-depth study of the components of polymyxins is the key to controlling the quality of this class of antibiotics.Similarities and variations of components present significant analytical challenges.A two-dimensional(2D)liquid chromatography-mass spectrometry(LC-MS)method was established for screening and comprehensive profiling of compositions of the antibiotic colistimethate sodium(CMS).A high concentration of phosphate buffer mobile phase was used in the first-dimensional LC system to get the components well separated.For efficient and high-accuracy screening of CMS,a targeted method based on a self-constructed high resolution(HR)mass spectrum database of CMS components was established.The database was built based on the commercial MassHunter Personal Compound Database and Library(PCDL)software and its accuracy of the compound matching result was verified with six known components before being applied to genuine sample screening.On this basis,the unknown peaks in the CMS chromatograms were deduced and assigned.The molecular formula,group composition,and origins of a total of 99 compounds,of which the combined area percentage accounted for more than 95％of CMS components,were deduced by this 2D-LC-MS method combined with the MassHunter PCDL.This profiling method was highly efficient and could distinguish hundreds of components within 3 h,providing reliable results for quality control of this kind of complex drugs.

Objective:To screen out the disinfection procedure and disinfectant suitable for the actual production of specific pathogen free(SPF)chicken embryo eggs,so as to ensure the disinfection effect of specific pathogen free(SPF)chicken embryo eggs in vaccine production.Methods:This study compares the microbial counting methods of soaking,swabbing with cotton swabs and pouring after thin-film filtration for SPF chicken embryo eggs in a GMP production workshop,and selects the most suitable method for SPF chicken embryo egg microbial counting.Experi-mental groups A,B,and C use self-prepared concentrations of 1∶50 sporicidal agent dilution solution,1∶128 alka-line phenol salt dilution solution,and ready-to-use compound quaternary ammonium disinfectant(sterile),respec-tively,and follow the actual disinfection procedures in the workshop to disinfect and sample the surfaces of SPF chicken embryo eggs entering different cleanliness grades,while using sterile water instead of disinfectant as the control group.The average bactericidal rate is calculated by recording the number of colonies and monitoring the viability of chicken embryo cells using microbial culture,and the disinfection effect of the three disinfectants on SPF chicken embryo eggs is evaluated.Results:The comparison of the results from the three methods shows that the method of sampling SPF chicken embryo eggs by immersion and then counting the microbial colonies through membrane filtration is superior to the other two methods.The final cleaning rate of the control group,which used sterilized injection water to clean the SPF chicken embryo eggs,was 91.67％to 96.97％,while the final steriliza-tion rate of the experimental group,which used the above three disinfectants to disinfect the SPF chicken embryo eggs,was 100.00％.By comparing the cell counts of the experimental group and the control group,it was found that the live cell density of the control group was(6.03-6.25)× 105 cells·mL-1,and that of the experimental groups A-C was(6.08-6.17)× 105 cells·mL-1,(5.99-6.25)× 105 cells·mL-1,and(5.87-6.21)× 105 cells·mL-1 respectively;the cell viability of the control group was 90.33％to 91.35％,and that of the experi-mental groups A-C was 88.25％to 92.12％,89.45％to 93.59％,and 88.02％to 92.89％respectively.Through statistical analysis,it was found that the P values of all experimental groups compared with the control group were greater than 0.05,indicating no statistically significant difference.Conclusion:By comparing the dis-infection effects,cell density and cell viability of the three disinfectants and comprehensively considering factors such as cost and risk of the three disinfectants,1∶50 sporicide dilution,1∶128 alkaline phenolate dilution and ready-to-use compound quaternary ammonium salt disinfectant(sterile)can all be used for the daily surface disin-fection of SPF chicken embryo eggs in the production workshop.The selection of an appropriate disinfectant should be based on specific application scenarios and requirements.

Isoflavones which mainly distributed in leguminous plants have plenty of health benefits.Isoflavone synthase(IFS)is a membrane-associated cytochrome P450 enzyme(CYP450)which carries out the unique aryl-ring migration and hydroxylation.So far,few crystal structures of plant P450s have been obtained.We determined the crystal structure of IFS from Medicago truncatula at 1.9 ? by MAD method using a selenomethionine substituted crystal and conducted molecular docking and mutagenesis study.The structure of IFS complexed with imidazole exhibits the helix Ⅰa-loop-helix Ⅰβ motif which cor-responds to helix Ⅰ of other P450s.Compared with structures of common P450s,IFS/imidazole structure contains an extra domain,i.e.,the γ-domain.The structure reveals a homodimer in which the γ-domain of one molecule interacts with the β-domain of another.The plane of heme group makes an angle of ap-proximately 40° with the helix Ⅰa-loop-helix Ⅰβ motif.Molecular docking combined with mutagenesis study suggested that Trp-128 and Asp-300 might play important roles in substrate binding and recogni-tion.Phe-301,Ser-303 and Gly-305 from the helix Ⅰa-loop-helix Ⅰβ motif may play important roles in the aryl-ring migration.These novel structural features reveal insights into the unique reaction mechanism of IFS and provide a basis for engineering IFS in leguminous crops for health purpose.

Objective To investigate the distribution and antimicrobial resistance profiles of common pathogens isolated from cerebrospinal fluid(CSF)in CHINET program from 2015 to 2021.Methods The bacterial strains isolated from CSF were identified in accordance with clinical microbiology practice standards.Antimicrobial susceptibility test was conducted using Kirby-Bauer method and automated systems per the unified CHINET protocol.Results A total of 14 014 bacterial strains were isolated from CSF samples from 2015 to 2021,including the strains isolated from inpatients(95.3％)and from outpatient and emergency care patients(4.7％).Overall,19.6％of the isolates were from children and 80.4％were from adults.Gram-positive and Gram-negative bacteria accounted for 68.0％and 32.0％,respectively.Coagulase negative Staphylococcus accounted for 73.0％of the total Gram-positive bacterial isolates.The prevalence of MRSA was 38.2％in children and 45.6％in adults.The prevalence of MRCNS was 67.6％in adults and 69.5％in children.A small number of vancomycin-resistant Enterococcus faecium(2.2％)and linezolid-resistant Enterococcus faecalis(3.1％)were isolated from adult patients.The resistance rates of Escherichia coli and Klebsiella pneumoniae to ceftriaxone were 52.2％and 76.4％in children,70.5％and 63.5％in adults.The prevalence of carbapenem-resistant E.coli and K.pneumoniae(CRKP)was 1.3％and 47.7％in children,6.4％and 47.9％in adults.The prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)and Pseudomonas aeruginosa(CRPA)was 74.0％and 37.1％in children,81.7％and 39.9％in adults.Conclusions The data derived from antimicrobial resistance surveillance are crucial for clinicians to make evidence-based decisions regarding antibiotic therapy.Attention should be paid to the Gram-negative bacteria,especially CRKP and CRAB in central nervous system(CNS)infections.Ongoing antimicrobial resistance surveillance is helpful for optimizing antibiotic use in CNS infections.