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: CRISPR-Cas protects bacteria from exogenous DNA invasion and is associated with bacterial biofilm formation and pathogenicity. METHODS: We analyzed the type I-F CRISPR-Cas system of Legionella pneumophila WX48, including Cas1, Cas2-Cas3, Csy1, Csy2, Csy3, and Cas6f, along with downstream CRISPR arrays. We explored the effects of the CRISPR-Cas system on the in vitro growth, biofilm-forming ability, and pathogenicity of L. pneumophila through constructing gene deletion mutants. RESULTS: The type I-F CRISPR-Cas system did not affect the in vitro growth of wild-type or mutant strains. The biofilm formation and intracellular proliferation of the mutant strains were weaker than those of the wild type owing to the regulation of type IV pili and Dot/Icm type IV secretion systems. In particular, Cas6f deletion strongly inhibited these processes. CONCLUSION The type I-F CRISPR-Cas system may reduce biofilm formation and intracellular proliferation in L. pneumophila.
Legionella pneumophila/pathogenicity* ; CRISPR-Cas Systems ; Biofilms/growth & development* ; Phenotype ; Bacterial Proteins/metabolism* ; Gene Deletion

AIM To establish a rapid quantitative analysis model for saponins in Paris polyphylla var.yunnanensis(PPY)by near infrared spectroscopy.METHODS The contents of polyphyllins Ⅰ,Ⅱ,Ⅶ and there total content in PPY were determined by HPLC,while spectral data within the range of 10 000 to 4 000 cm-1 were collected.A quantitative analysis model was established by combining these data with partial least squares regression(PLSR).Multivariate scatter correction(MSC)and vector normalization(SNV)were applied prior to further preprocessing the spectra with original,first-order derivative(1stD),or second-order derivative(2ndD)treatments.Lastly,the model was optimized through non-smoothing(NS),Norris Derivative filtering(Nd),and Savitzky-Golay filtering(S-G)method.Model stability was evaluated based on correlation coefficients and variance.The predicted contents of each saponin component in the validation set samples were calculated.RESULTS The contents of polyphyllins Ⅰ,Ⅱ,Ⅶ were 0.42-17.98,0.46-10.44,0.23-3.86 mg/g,respectively.The total content ranged from 2.91 to 22.1 mg/g.The optimal parameters of three saponins were achieved when selecting the MSC+2ndD+S-G pretreatment method.The corresponding ratio of line segment length to segment gap was 13∶5,15∶5,11∶5,with correlation coefficients of 0.982,0.930,0.958,respectively.The root mean square errors of calibration(RMSEC)were 0.702,0.797,0.238,and the root mean square errors of prediction(RMSEP)were 1.120,0.835,0.304,respectively.The optimal parameters for the total content were obtained when selecting the MSC+2ndD+NS pretreatment method,with a correlation coefficient of 0.970,a RMSEC of 1.090,and a RMSEP of 1.740.CONCLUSION This accurate and rapid method can be used for detection of saponin contents in P.Polyphylla.

Objective:To evaluate the long-term protective efficacy of the recombinant Chinese hamster ovary cell-derived hepatitis B vaccine（CHO-HepB）26 years post-vaccination in the rural China.Methods:Zhengding county，Hebei province was designated as a rural monitoring site for CHO-HepB efficacy. Study participants included individuals born between 1997 and 1999 who had completed the three-dose CHO-HepB primary series without booster doses. A cross-sectional survey was conducted in late 2024 using random sampling. Demographic and vaccination history data were collected via questionnaires，and hepatitis B virus（HBV）serological markers were detected using chemiluminescence. Historical surveillance data were integrated to infer infection statuses of HBsAg-positive individuals and evaluate longitudinal trends in anti-HBs seropositivity and antibody titers.Results:Among 178 participants（mean time since vaccination：26.2 years），the seroprevalence rates were 0.6% for HBsAg（95% CI：0.0%-1.6%），64.6% for anti-HBs（95% CI：57.6%-71.6%），and 1.1% for anti-HBc（95% CI：0.0%-2.7%）. Compared to the pre-vaccination baseline HBsAg positivity of 11.3% in children under 10 years of age，the estimated vaccine protection rate was 95%. Two notable cases were identified：one with concurrent HBsAg and anti-HBc positivity and one with anti-HBs and anti-HBc positivity，suggestive of transient HBV exposure（1999—2009）without chronicity. Natural immune boosting was inferred for the latter case based on anti-HBs titer dynamics. Longitudinal analysis of four prior cross-sectional surveys（2005，2009，2013，and 2017）revealed no significant upward trends in HBsAg and anti-HBc positivity（both P>0.05）over 26 years，while anti-HBs seropositivity declined significantly（ P<0.05）from 6 to 26 years post-vaccination. Conclusion:The CHO-HepB vaccine demonstrates sustained immunological persistence and robust long-term protection up to 26 years post-immunization. Continued emphasis on rigorous implementation of mother-to-child transmission prevention strategies is critical for future hepatitis B control.

Objective:To investigate the value of 0.55 T MRI scanner using deep-learning (DL) reconstruction in evaluating pulmonary tumors.Methods:The study was a cross-sectional study. Sixty-one patients with pulmonary tumors on CT images were prospectively collected from May to September 2024 in Peking University First Hospital, including 37 males and 24 females, and aged 46?89 (68±9) years old. All patients underwent lung scan on a 0.55 T MRI, using diffusion weighted imaging(DWI) sequence with b-values of 0 and 800 s/mm 2. According to whether DL reconstruction was used and the number of acquisitions, they were divided into DWI-DL 5∶30 group (DL, number of averages=10, acquisition time=5 min 30 s),DWI-DL 3∶22 group (DL, number of averages=5, acquisition time=3 min 22 s), and DWI-C group (GRAPPA, number of averages=10, acquisition time=5 min 30 s). The obtained images were evaluated subjectively (Likert score) and objectively [signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR)]. Meanwhile the apparent diffusion coefficient (ADC) value of the tumors was measured. Friedman nonparametric test was used for comparison among the three groups and Bonferroni method was used for pairwise comparison. Results:The subjective scores, SNR, and CNR were significantly different among DWI-DL 5∶30 group, DWI-DL 3∶22 group, and DWI-C group( χ 2=9.69,87.56,88.62, P=0.008,<0.001,<0.001). Bonferroni method results showed that the subjective scores, SNR, and CNR of DWI-DL 5∶30 group were higher than those of DWI-DL 3∶22 group and DWI-C group ( P<0.05); However, the subjective scores, SNR, and CNR did not significantly differ between DWI-DL 3∶22 group and DWI-C group ( P>0.05). The ADC values of the tumors were not significantly different among DWI-DL 5∶30 group, DWI-DL 3∶22 group, and DWI-C group (χ 2=5.95, P=0.510). Conclusion:The DWI reconstructed using DL has better or similar image quality to conventional DWI in evaluating pulmonary tumors and significantly reduces scanning time, which has certain clinical application value.

AIM To investigate the protective effects of Shuangyi Qushi Tongluo Capsules(Shuangyi Capsules)on Dexamethasone(Dex)induced osteoporosis in mice.METHODS The C57BL/6J mice were randomly divided into the control group,the model group,the Xianling Gubao Capsules group(1.5 g/kg),and the low-dose,moderate-dose,and high-dose Shuangyi Capsules groups(0.6,1.2,and 2.4 g/kg).The mouse model of osteoporosis was induced by 8-week intraperitoneal injection of Dex sodium phosphate injection(5 mg/kg).The mice had their femur osteogenesis observed with hematoxylin and eosin(HE)staining and tartrate-resistant acid phosphatase(TRAP)staining;their serum alkaline phosphatase(ALP)and osteocalcin(BGP)activities detected by ELISA;their femoral mRNA expressions of Col-Ⅰ,OCN,and OPN detected by RT-qPCR;and their femoral protein expressions of OPG and RANKL detected by Western blot.Upon the MC3T3-E1 cells exposed to Dex and Shuangyi Capsules,their viability was evaluated by CCK-8 assay;their mineralization determined by alkaline phosphatase staining and alizarin red staining(ARS);and their intracellular ROS level detected using DCFH-DA probe.RESULTS Compared with the model group,Shuangyi Capsules groups demonstrated improved fracture of femoral trabeculae and reduced number of osteoclasts;increased serum ALP and BGP activities(P＜0.05,P＜0.01);increased femoral expressions of Col-Ⅰ mRNA and OPG protein(P＜0.05,P＜0.01);and decreased RANKL protein expression(P＜0.05).Compared with the MC3T3-E1 cells stimulated by Dex,those underwent further treatment of Shuangyi Capsules demonstrated increased cell viability and ALP activity(P＜0.05,P＜0.01);increased mineralization and calcium nodule formation;increased expressions of Col-Ⅰ,OCN,OPN mRNA and OPG protein(P＜0.05,P＜0.01);decreased RANKL protein expression(P＜0.05,P＜0.01);and reduced ROS levels.CONCLUSION Shuangyi Capsules ameliorate Dex-induced osteoporosis in mice by suppressing osteoclast overactivation,enhancing osteoblast activity,and stimulating bone formation through modulation of Col-Ⅰ,OCN,OPN mRNA and OPG/RANKL protein levels.

Objective:To investigate the value of 0.55 T MRI scanner using deep-learning (DL) reconstruction in evaluating pulmonary tumors.Methods:The study was a cross-sectional study. Sixty-one patients with pulmonary tumors on CT images were prospectively collected from May to September 2024 in Peking University First Hospital, including 37 males and 24 females, and aged 46?89 (68±9) years old. All patients underwent lung scan on a 0.55 T MRI, using diffusion weighted imaging(DWI) sequence with b-values of 0 and 800 s/mm 2. According to whether DL reconstruction was used and the number of acquisitions, they were divided into DWI-DL 5∶30 group (DL, number of averages=10, acquisition time=5 min 30 s),DWI-DL 3∶22 group (DL, number of averages=5, acquisition time=3 min 22 s), and DWI-C group (GRAPPA, number of averages=10, acquisition time=5 min 30 s). The obtained images were evaluated subjectively (Likert score) and objectively [signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR)]. Meanwhile the apparent diffusion coefficient (ADC) value of the tumors was measured. Friedman nonparametric test was used for comparison among the three groups and Bonferroni method was used for pairwise comparison. Results:The subjective scores, SNR, and CNR were significantly different among DWI-DL 5∶30 group, DWI-DL 3∶22 group, and DWI-C group( χ 2=9.69,87.56,88.62, P=0.008,<0.001,<0.001). Bonferroni method results showed that the subjective scores, SNR, and CNR of DWI-DL 5∶30 group were higher than those of DWI-DL 3∶22 group and DWI-C group ( P<0.05); However, the subjective scores, SNR, and CNR did not significantly differ between DWI-DL 3∶22 group and DWI-C group ( P>0.05). The ADC values of the tumors were not significantly different among DWI-DL 5∶30 group, DWI-DL 3∶22 group, and DWI-C group (χ 2=5.95, P=0.510). Conclusion:The DWI reconstructed using DL has better or similar image quality to conventional DWI in evaluating pulmonary tumors and significantly reduces scanning time, which has certain clinical application value.

Objective:To evaluate the long-term protective efficacy of the recombinant Chinese hamster ovary cell-derived hepatitis B vaccine（CHO-HepB）26 years post-vaccination in the rural China.Methods:Zhengding county，Hebei province was designated as a rural monitoring site for CHO-HepB efficacy. Study participants included individuals born between 1997 and 1999 who had completed the three-dose CHO-HepB primary series without booster doses. A cross-sectional survey was conducted in late 2024 using random sampling. Demographic and vaccination history data were collected via questionnaires，and hepatitis B virus（HBV）serological markers were detected using chemiluminescence. Historical surveillance data were integrated to infer infection statuses of HBsAg-positive individuals and evaluate longitudinal trends in anti-HBs seropositivity and antibody titers.Results:Among 178 participants（mean time since vaccination：26.2 years），the seroprevalence rates were 0.6% for HBsAg（95% CI：0.0%-1.6%），64.6% for anti-HBs（95% CI：57.6%-71.6%），and 1.1% for anti-HBc（95% CI：0.0%-2.7%）. Compared to the pre-vaccination baseline HBsAg positivity of 11.3% in children under 10 years of age，the estimated vaccine protection rate was 95%. Two notable cases were identified：one with concurrent HBsAg and anti-HBc positivity and one with anti-HBs and anti-HBc positivity，suggestive of transient HBV exposure（1999—2009）without chronicity. Natural immune boosting was inferred for the latter case based on anti-HBs titer dynamics. Longitudinal analysis of four prior cross-sectional surveys（2005，2009，2013，and 2017）revealed no significant upward trends in HBsAg and anti-HBc positivity（both P>0.05）over 26 years，while anti-HBs seropositivity declined significantly（ P<0.05）from 6 to 26 years post-vaccination. Conclusion:The CHO-HepB vaccine demonstrates sustained immunological persistence and robust long-term protection up to 26 years post-immunization. Continued emphasis on rigorous implementation of mother-to-child transmission prevention strategies is critical for future hepatitis B control.