Objective:To compare the diagnostic value of semi-quantitative parameters of fluorine 18-labelled prostate-specific membrane antigen( 18F-PSMA)positron emission tomography /computed tomography(PET/CT)and the Prostate-specific Membrane Antigen Reporting and Data System(PSMA-RADS)score for identifying benign and malignant oligo-PSMA-avid bone lesions(1-5 lesions)in elderly patients with prostate cancer. Methods:A retrospective analysis was conducted on 157 prostate cancer patients who underwent 18F-PSMA PET/CT examinations at Beijing Hospital from October 2022 to August 2024.According to the inclusion and exclusion criteria, a total of 63 patients were selected.All patients underwent 18F-PSMA PET/CT examination for the purpose of initial staging or detecting lesions with biochemical recurrence.PSMA-avid bone lesions were evaluated using the PSMA-RADS version 2.0 scoring system and the semi-quantitative parameters were measured on PSMA PET/CT images.According to the comprehensive diagnostic criteria, PSMA-avid bone lesions were divided into metastatic group and non-metastatic group.The differences in PSMA-RADS scores, semi-quantitative parameters, bone density abnormalities, and lesion distribution were compared between the two groups.Multivariate logistic regression analysis was performed to determine the factors related to the bone metastasis in prostate cancer.By plotting the receiver operating characteristic(ROC)curves and calculating the area under the curve(AUC), factors with better diagnostic performance were evaluated and screened, and the optimal diagnostic threshold for each factor in diagnosing bone metastasis was determined. Results:There were a total of 129 PSMA-avid bone lesions for 63 patients(aged 60-84 years, median age 69 years), including 35 lesions(27.1%)in the metastatic group and 94 lesions(72.9%)in the non-metastatic group.The differences between metastatic group and non-metastatic group in PSMA-RADS scores[5(4, 5) vs.3(3, 3)], maximum standardized uptake value(SUV max)[12.6(7.0, 18.4) vs.4.7(3.5, 5.9)], lesion SUV max/mediastinal blood pool SUV max ratio(lesion-to-blood pool ratio, LBR)[5.4(3.0, 8.3) vs.1.7(1.4, 2.2)], lesion SUV max/liver SUV max ratio(lesion-to-liver ratio, LLR)[2.6(1.6, 4.1) vs.0.8(0.7, 1.1)], PSMA receptor expressing tumor volume(PSMA-TV)[0.6(0.3, 1.0) vs.1.0(0.7, 1.5)], total lesion of PSMA(TL-PSMA)[4.4(2.4, 7.0) vs.2.4(1.7, 3.9)], proportion of changes in osteogenic bone density[77.1%(27/35) vs.2.1%(2/94)], proportion of lesions located in the ribs[14.3%(5/35) vs.46.8%(44/94)], and proportion of lesions located in the pelvis[54.3%(19/35) vs.20.2%(19/94)]were all statistically significant(all P<0.05). Multivariate logistic regression analysis indicated that none of the variables with statistically significant differences between groups above were independent risk factors for osseous metastasis in prostate cancer(all P>0.05). Among them, The PSMA-RADS score, LLR, LBR, and SUV max all had good diagnostic efficacy for osseous metastasis, with 0.995(95% CI: 0.987-1.000), 0.923(95% CI: 0.869-0.977), 0.898(95% CI: 0.828-0.967), and 0.890(95% CI: 0.820-0.961), respectively.The cut-off values for diagnosing osseous metastasis were 4 score for PSMA-RADS score, 0.934 for LLR, 1.990 for LBR, and 5.47 for SUV max, respectively.According to Delong's test, there were statistically significant differences in AUC between PSMA-RADS score and 18F-PSMA PET/CT semi-quantitative parameters(LLR, LBR, and SUV max)( Z-values were 2.677, 2.776, and 2.929, respectively, and P-values were 0.007, 0.006, and 0.003, respectively). Conclusions:The PSMA-RADS score(Version 2.0)and 18F-PSMA PET/CT semi-quantitative parameters(LLR, LBR, and SUV max)both have good diagnostic value in differentiating benign and malignant PSMA-avid bone lesions in elderly patients with prostate cancer, among which the PSMA-RADS score has the best diagnostic efficacy.

Objective:To utilize the left ventricular myocardial work（LVMW）technique for early identification of myocardial damage in patients with fabry disease（FD）.Methods:In an observational cross-sectional study，35 patients with FD who visited the Second Hospital of Hebei Medical University from February 2023 to April 2024 were included. They were categorized into two groups based on left ventricular mass index（LVMI）：the non-left ventricular hypertrophy group（LVH-FD group，14 cases）and the left ventricular hypertrophy group（LVH+FD group，21 cases）. Further gender-stratified analysis was performed on parameters related to left ventricular global longitudinal strain（LVGLS）and LVMW. Additionally，for the FD group with normal LVGLS，a comparison of their LVMW-related parameters was made with a control group. A control group consisting of 28 healthy subjects from the same period was selected for comparison. The LVGLS，global work index（LVGWI），global constructive work（LVGCW），global wasted work（LVGWW），and global work efficiency（LVGWE）of the three groups were analyzed using two-dimensional speckle tracking and non-invasive myocardial work techniques，and intergroup comparisons of these parameters were performed. Pearson's linear correlation was applied to analyse the correlation between LVGWI，LVGWE and LVMI.Results:① According to the LVMI grouping results，compared with the control group，the LVH-FD group showed decreased LVGWI（ P<0.05），while the LVH+FD group exhibited reductions in LVGLS，LVGWI，and LVGWE（all P<0.05）. Compared to the LVH-FD group，the LVH+FD group demonstrated lower LVGLS，LVGWI，and LVGWE（all P<0.05）. ② Gender subgroup analysis revealed that in the female subgroup，no statistically significant differences were observed in LVGLS，LVGWI，and LVGWE between the female control group and the female LVH-FD group（all P>0.05）. However，the female LVH+ FD group showed decreased LVGLS，LVGWI，and LVGWE compared to both the female control group（all P<0.05）and the female LVH-FD group（all P<0.05）. In the male subgroup，compared to the male control group，the male LVH-FD group had reduced LVGWI（ P<0.05）but no significant differences in LVGLS or LVGWE（both P>0.05）. The male LVH+ FD group displayed lower LVGLS，LVGWI，and LVGWE compared to both the male control group（all P<0.05）and the male LVH- FD group（all P<0.05）. ③Compared with the control group，the LVGLS-normal FD group had a reduced LVGWI（ P<0.05），while there were no statistically significant differences in LVGLS，LVGWE，LVGCW，and LVGWW between these two groups（all P>0.05）. ④LVGWI and LVGWE were negatively correlated with LVMI（ r=-0.617，-0.707；both P<0.001）. Conclusions:LVMW can detect early cardiac dysfunction in patients with FD and is of guiding value for their clinical management.

Objective To explore the valve regurgitation status of left heart after the implantation of left ventricular assist device (LVAD) and its effect on prognosis of patients with LVAD implantation. Methods A total of 35 patients with cardiomyopathy who underwent magnetic levitation LVAD implantation at Zhongshan Hospital, Fudan University from February 2021 to July 2024 were retrospectively selected. Clinical data during hospitalization were collected, including preoperative basic data and postoperative valve regurgitation status. Telephone follow-ups were conducted to monitor patients’ survival status and transthoracic echocardiography was used to assess left valve function. Kaplan-Meier survival curves and log-rank test were employed to compare the survival rate of patients with different levels of valve regurgitation. Results The 35 patients had a mean age of (53.9±11.1) years, with 85.7% male, and 3 patients (8.6%) died during hospitalization. Preoperatively, 17 patients (48.6%) had moderate or greater mitral regurgitation, while all 35 patients had less than moderate aortic regurgitation. One month postoperatively, thirty patients were followed up, among which 24 patients (80%) had less than moderate mitral regurgitation, including 11 cases with alleviated regurgitation compared to pre-surgery; 6 patients (20%) had moderate or greater mitral regurgitation, including 4 cases with stable regurgitation and 2 cases with progression of regurgitation compared to pre-surgery; 2 patients (6.7%) had progression of aortic regurgitation to moderate or greater. The follow-up time was 1.2 (1.0, 2.1) years, with 1-year survival rate of 91.4% and 3-year survival rate of 71.1%. Survival analysis showed that the 3-year survival rate of patients with moderate or greater mitral regurgitation one month postoperatively was significantly lower than that of patients with less than moderate regurgitation (66.7% vs 83.3%, P＝0.046). Conclusions After the implantation of magnetic levitation LVAD, most patients showed improvement in mitral regurgitation, while aortic regurgitation remained unchanged. The degree of mitral regurgitation one month postoperatively is associated with prognosis.

Objective:To compare the diagnostic value of semi-quantitative parameters of fluorine 18-labelled prostate-specific membrane antigen( 18F-PSMA)positron emission tomography /computed tomography(PET/CT)and the Prostate-specific Membrane Antigen Reporting and Data System(PSMA-RADS)score for identifying benign and malignant oligo-PSMA-avid bone lesions(1-5 lesions)in elderly patients with prostate cancer. Methods:A retrospective analysis was conducted on 157 prostate cancer patients who underwent 18F-PSMA PET/CT examinations at Beijing Hospital from October 2022 to August 2024.According to the inclusion and exclusion criteria, a total of 63 patients were selected.All patients underwent 18F-PSMA PET/CT examination for the purpose of initial staging or detecting lesions with biochemical recurrence.PSMA-avid bone lesions were evaluated using the PSMA-RADS version 2.0 scoring system and the semi-quantitative parameters were measured on PSMA PET/CT images.According to the comprehensive diagnostic criteria, PSMA-avid bone lesions were divided into metastatic group and non-metastatic group.The differences in PSMA-RADS scores, semi-quantitative parameters, bone density abnormalities, and lesion distribution were compared between the two groups.Multivariate logistic regression analysis was performed to determine the factors related to the bone metastasis in prostate cancer.By plotting the receiver operating characteristic(ROC)curves and calculating the area under the curve(AUC), factors with better diagnostic performance were evaluated and screened, and the optimal diagnostic threshold for each factor in diagnosing bone metastasis was determined. Results:There were a total of 129 PSMA-avid bone lesions for 63 patients(aged 60-84 years, median age 69 years), including 35 lesions(27.1%)in the metastatic group and 94 lesions(72.9%)in the non-metastatic group.The differences between metastatic group and non-metastatic group in PSMA-RADS scores[5(4, 5) vs.3(3, 3)], maximum standardized uptake value(SUV max)[12.6(7.0, 18.4) vs.4.7(3.5, 5.9)], lesion SUV max/mediastinal blood pool SUV max ratio(lesion-to-blood pool ratio, LBR)[5.4(3.0, 8.3) vs.1.7(1.4, 2.2)], lesion SUV max/liver SUV max ratio(lesion-to-liver ratio, LLR)[2.6(1.6, 4.1) vs.0.8(0.7, 1.1)], PSMA receptor expressing tumor volume(PSMA-TV)[0.6(0.3, 1.0) vs.1.0(0.7, 1.5)], total lesion of PSMA(TL-PSMA)[4.4(2.4, 7.0) vs.2.4(1.7, 3.9)], proportion of changes in osteogenic bone density[77.1%(27/35) vs.2.1%(2/94)], proportion of lesions located in the ribs[14.3%(5/35) vs.46.8%(44/94)], and proportion of lesions located in the pelvis[54.3%(19/35) vs.20.2%(19/94)]were all statistically significant(all P<0.05). Multivariate logistic regression analysis indicated that none of the variables with statistically significant differences between groups above were independent risk factors for osseous metastasis in prostate cancer(all P>0.05). Among them, The PSMA-RADS score, LLR, LBR, and SUV max all had good diagnostic efficacy for osseous metastasis, with 0.995(95% CI: 0.987-1.000), 0.923(95% CI: 0.869-0.977), 0.898(95% CI: 0.828-0.967), and 0.890(95% CI: 0.820-0.961), respectively.The cut-off values for diagnosing osseous metastasis were 4 score for PSMA-RADS score, 0.934 for LLR, 1.990 for LBR, and 5.47 for SUV max, respectively.According to Delong's test, there were statistically significant differences in AUC between PSMA-RADS score and 18F-PSMA PET/CT semi-quantitative parameters(LLR, LBR, and SUV max)( Z-values were 2.677, 2.776, and 2.929, respectively, and P-values were 0.007, 0.006, and 0.003, respectively). Conclusions:The PSMA-RADS score(Version 2.0)and 18F-PSMA PET/CT semi-quantitative parameters(LLR, LBR, and SUV max)both have good diagnostic value in differentiating benign and malignant PSMA-avid bone lesions in elderly patients with prostate cancer, among which the PSMA-RADS score has the best diagnostic efficacy.

Objective:To utilize the left ventricular myocardial work（LVMW）technique for early identification of myocardial damage in patients with fabry disease（FD）.Methods:In an observational cross-sectional study，35 patients with FD who visited the Second Hospital of Hebei Medical University from February 2023 to April 2024 were included. They were categorized into two groups based on left ventricular mass index（LVMI）：the non-left ventricular hypertrophy group（LVH-FD group，14 cases）and the left ventricular hypertrophy group（LVH+FD group，21 cases）. Further gender-stratified analysis was performed on parameters related to left ventricular global longitudinal strain（LVGLS）and LVMW. Additionally，for the FD group with normal LVGLS，a comparison of their LVMW-related parameters was made with a control group. A control group consisting of 28 healthy subjects from the same period was selected for comparison. The LVGLS，global work index（LVGWI），global constructive work（LVGCW），global wasted work（LVGWW），and global work efficiency（LVGWE）of the three groups were analyzed using two-dimensional speckle tracking and non-invasive myocardial work techniques，and intergroup comparisons of these parameters were performed. Pearson's linear correlation was applied to analyse the correlation between LVGWI，LVGWE and LVMI.Results:① According to the LVMI grouping results，compared with the control group，the LVH-FD group showed decreased LVGWI（ P<0.05），while the LVH+FD group exhibited reductions in LVGLS，LVGWI，and LVGWE（all P<0.05）. Compared to the LVH-FD group，the LVH+FD group demonstrated lower LVGLS，LVGWI，and LVGWE（all P<0.05）. ② Gender subgroup analysis revealed that in the female subgroup，no statistically significant differences were observed in LVGLS，LVGWI，and LVGWE between the female control group and the female LVH-FD group（all P>0.05）. However，the female LVH+ FD group showed decreased LVGLS，LVGWI，and LVGWE compared to both the female control group（all P<0.05）and the female LVH-FD group（all P<0.05）. In the male subgroup，compared to the male control group，the male LVH-FD group had reduced LVGWI（ P<0.05）but no significant differences in LVGLS or LVGWE（both P>0.05）. The male LVH+ FD group displayed lower LVGLS，LVGWI，and LVGWE compared to both the male control group（all P<0.05）and the male LVH- FD group（all P<0.05）. ③Compared with the control group，the LVGLS-normal FD group had a reduced LVGWI（ P<0.05），while there were no statistically significant differences in LVGLS，LVGWE，LVGCW，and LVGWW between these two groups（all P>0.05）. ④LVGWI and LVGWE were negatively correlated with LVMI（ r=-0.617，-0.707；both P<0.001）. Conclusions:LVMW can detect early cardiac dysfunction in patients with FD and is of guiding value for their clinical management.

Objective:To explore the diagnostic value of 18F-prostate specific membrane antigen (PSMA) PET/CT PRIMAY score combined with multiparameter MRI (mpMRI) PI-RADS score for clinically significant prostate cancer (CsPCa). Methods:The data of 63 patients with prostate cancer who underwent radical prostatectomy at Beijing Hospital from January 2019 to December 2023 were retrospectively analyzed. The median age was 70 (64, 75) years old with prostate-specific antigen (PSA) level of 8.46 (5.40, 14.80) ng/ml. All patients underwent 18F-PSMA PET/CT and mpMRI examination before surgery, and pathological large sections of prostate specimens were made after surgery. The prostate lesions were diagnosed and located by two radiologists and one pathologist respectively. Lesions with Gleason scores (GS)≥3+ 4 from the surgical pathology were diagnosed with CsPCa, and lesions with negative or GS=6 were diagnosed with non-CsPCa. The PSMA PET/CT images were evaluated using the PRIMARY study criteria (5-level PRlMARY score): no pattern (score of 1), diffuse transition zone or central zone(not focal) (score of 2), focal transition zone(score of 3), focal peripheral zone(score of 4), or an SUV max of at least 12 (score of 5). The degree of uptake of imaging agent in prostate lesions was semi-quantitatively evaluated using lesion-to-background ratios (LBR) of SUV max. MpMRI was evaluated according to the Prostate Imaging Reporting and Data System (PI-RADS) version 2.1. The patients were divided into CsPCa group and non-CsPCa group based on patients and lesions. Mann-Whitney U test and chi-square test were used to compare the differences between groups. Multivariate logistic regression analysis was performed to determine the independent predictive factors of CsPCa. Receiver operator characteristic (ROC) curve was used to determine the optimal diagnostic threshold for each independent predictor. Predictive models were constructed for PRIMARY score, PI-RADS score, and their combined application, and the diagnostic performance of each model for CsPCa was compared. Results:Of all 63 patients, there were 54 cases in CsPCa group (85.7%) and 9 cases in non-CsPCa group (14.3%).There was significant difference between CsPCa group and non-CsPCa group in the serum PSA level [9.64 (6.1, 15.3) ng/ml vs. 5.6 (4.6, 7.6) ng/ml]( P<0.05). There was no statistically significant difference in age [71 (64, 75) years vs. 65 (63, 69) years], and number of lesions [2 (1, 2) vs. 2 (1, 3)] (all P>0.05). Of all 109 lesions, there were 81 lesions in CsPCa group(including 49 lesions with Gleason score = 3+ 4, 16 lesions with Gleason score=4+ 3, 14 lesions with Gleason score = 8, and 2 lesions with Gleason score>8) and 28 lesions in non-CsPCa group(including 14 lesions with Gleason score = 3+ 3 and 14 with benign prostate lesions). There was significant difference between CsPCa group and non-CsPCa group in PRIMARY score [4 (3, 5) vs. 2 (1, 4)], LBR [2.69 (2.08, 4.48) vs. 1.89 (1.45, 2.48)], PI-RADS score [4 (3, 5) vs. 2 (2, 3)] (all P<0.05). There was no statistically significant difference in the lesion distribution including the number of lesions located in the transition zone [15(18.5%) vs. 8(28.6%)] and in the peripheral zone[66(81.5%) vs. 20(71.4%)]( P>0.05). Multivariate logistic regression analysis indicated that PRIMARY score ( OR=2.134, 95% CI 1.429-3.187) and PI-RADS score ( OR=2.689, 95% CI 1.618-4.469) were independent predictors of CsPCa (both P<0.01). ROC curves analysis revealed that the cut-off value for diagnosing CsPCa was both 3 for PRIMARY score and PI-RADS score. The accuracy for PRIMARY score, PI-RADS score, and their combined complication in diagnosing CsPCa was 72%, 67%, and 83%, respectively. The sensitivity was 72%, 63%, and 91%, and the specificity was 75%, 79%, and 57%, respectively. The positive predictive value was 89%, 89%, and 86%, and the negative predictive value was 48%, 42%, and 70%, respectively. The area under the curve of the PRIMARY score, PI-RADS score, and their combined complication of the ROC curve for CsPCa were 0.733 (95% CI 0.624-0.842), 0.708 (95% CI 0.599-0.817), and 0.743 (95% CI 0.623-0.862), respectively. The diagnostic efficacy of their combined complication was higher than PRIMARY score or PI-RADS score alone (both P<0.01). Conclusions:Both the 18F-PSMA PET/CT PRIMAY score and the mpMRI PI-RADS score have good diagnostic value for CsPCa. The combined application of the two imaging parameters can improve the accuracy, sensitivity, and negative predictive value, which have a higher diagnostic efficiency of CsPCa.

To investigate the role of chebulagic acid(CA)in regulating lipopolysaccharide(LPS)-in-duced inflammatory response in endometrial tissue of dairy cows,and to provide new ideas for the treatment and new drug development of endometritis in dairy cows.The endometrial tissues of dairy cows were isolated and cultured in vitro,stimulated with 1 mg/L LPS for 1 h and then co-cultured with CA(12.5,25.0,50.0,100.0 mg/L).Then the endometrial tissues of different treat-ment groups were collected for experiments.The protein secretion and gene expression levels of TNF-α,IL-6 and IL-1β were detected by ELISA and real-time fluorescence quantitative PCR.HE staining was used to observe the degree of endometrial tissue damage.The expressions of high mobility protein 1(HMGB-1)and hyaluronidase binding protein 2(HABP-2)were detected by immunofluorescence.The phosphorylation levels of ERK,p65 and IκBα were detected by Western blot.The results showed that the protein secretion levels of TNF-α at 6,24 h and IL-6 at 6,12 and 24 h,and the gene expression levels of IL-1β and IL-6 at 6,9,and 12 h and TNF-α at 6 h were sig-nificantly down-regulated after CA treatment with the LPS-induced endometrial tissue inflammation response model of dairy cows.HE staining showed that compared with the LPS group,the LPS+CA group had some improvements,the degree of epithelial cell exfoliation was reduced,the struc-ture of glands and blood vessels was relatively complete,the degree of inflammatory cell infiltra-tion was reduced,and there was no obvious necrosis or hemorrhage.The expression of HMGB-1 and HABP-2 in LPS+CA group was also significantly down-regulated.The phosphorylation levels of ERK,IκBα and p65 in the LPS+CA group were significantly decreased.In conclusion,CA can reduce LPS-induced inflammation in the endometrial tissue of dairy cows by inhibiting the activa-tion of MAPK and NF-κB pathways and down-regulating the expression of inflammatory factors in the uterine tissue.It is concluded that CA may be a potential therapeutic agent for endometritis in dairy cows and deserves further research and development.

ObjectiveTo explore the method of optimizing the performance of traditional Chinese medicine （TCM） syndrome diagnostic models using Stacking ensemble learning. MethodsTaking the construction of TCM syndrome diagnostic model for lung cancer as an example， 2598 cases of clinical symptoms and signs from lung cancer patients in 9 hospitals were used as independent variables （i.e.， feature variables）， TCM syndrome information as dependent variables， and the clinical data were divided into training set and testing set in 8：2 ratio according to random number table method using Python 3.7 software. The stable features of TCM syndrome of lung cancer were screened using chi-square test， Spearman's correlation test， and Least Absolute Shrinkage and Selection Operator （LASSO） logistic regression analysis； nine machine learning algorithms are trained， including support vector machines （SVMs）， k-nearest neighbors （KNN） algorithm， Random Forest （RF）， Extremely Randomized Trees， Extreme Gradient Boosting （XGBoost）， Lightweight Gradient Boosting （LightGBM）， Adaptive Boosting （AdaBoost）， Gradient Boosting （GB） and the multi-layer perceptron （MLP）， to obtain 9 basic models. Four models with better performance were screened out from the above basic models and fused to form a fusion model by using the Stacking ensemble learning， and the fusion model was trained twice by the above nine machine learning algorithms and evaluated by accuracy rate， micro-average ROC curves， area under the curve （AUC）， and confusion matrix metrics， to screen the optimal diagnostic model. ResultsAfter data processing， 79 stable features and 13 TCM syndromes were obtained. In the basic model training， the comprehensive performance of RF， ExtraTrees， MLP and SVM basic models were better， so the predicted distributions of the syndromes of these four models were used as the secondary training data， and nine fusion models were obtained based on the Stacking ensemble learning （SVM， KNN， RF， ExtraTree， XGBoost， LightGBM， GB， AdaBoost， MLP）. Among them， the XGBoost fusion model performed the best， with an accuracy of 0.850 and 0.838 in the training set and test set， respectively， an overfitting difference of 0.012， and an area under the micro-average ROC curve of 0.996. All fusion models showed an improvement in accuracy and area under the micro-average ROC curve compared with the base model in the test set. ConclusionTaking the TCM syndrome information of lung cancer as an example， the XGBoost fusion model has significant advantages in improving the diagnostic performance of TCM syndrome information of lung cancer through Stacking ensemble learning. It can be seen that the advantages of Stacking ensemble learning to integrate multiple models and effectively improve the diagnostic efficiency of TCM diagnostic models， which provided a methodological reference for similar studies.

Objective:To investigate the application effect of WeChat group combined with case-based learning (CBL) in probation teaching of vascular surgery.Methods:A total of 128 intern doctors of the seven-year medical program in vascular surgery were selected and divided into experimental group (WeChat group combined with CBL teaching) and control group (CBL teaching alone), and a unified assessment method was used to evaluate the mastery degree of professional theories and clinical knowledge and assess the teaching effect of these two teaching modes in vascular surgery. SPSS 22.0 was used to perform the t-test. Results:Compared with the control group, the experimental group had significantly higher scores of theoretical examination [(86.36±7.42) vs. (84.71±6.72)] and clinical examination [(88.44±7.62) vs. (86.22±6.41)], as well as significantly higher degrees of satisfaction with learning interest, classroom climate, self-learning ability, clinical thinking ability, and teamwork spirit.Conclusion:The teaching mode of WeChat group combined with CBL can improve the effect of the probation teaching of vascular surgery and the self-learning and clinical thinking abilities of intern doctors.

【Objective】 To understand the occupational exposure of blood center staff during blood collection and supply, analyze the influencing factors, explore preventive measures and improve the self-protection awareness of staff, so as to further improve the prevention of such occupational exposure in blood centers. 【Methods】 Seventy-two occupational exposure cases, which occurred and registered in Beijing Red Cross Blood Center from January 2010 to December 2021, were reviewed by retrospective survery methods, and such cases were classified and analyzed statistically. The incidence of blood-borne occupational exposure was compared by genders, departments, occurrence locations, education level, occupation type, work link, causes of exposure and body parts, so as to analyze the influencing factors, and then propose corresponding prevention strategies. 【Results】 From 2010 to 2021, a total of 72 blood-borne occupational exposure cases occurred. When classified by gender, the exposure rate of women was more than twice that of men; by age, the exposure rate of 18~25 years old was the highest, reaching 7.84%, but 26~40 years old group contributed the most cases, accounting for 70.83% (51/72); by working years, the exposure rate of staff with working years less than 3 years was relatively high, but the staff with 4~10 working years contributed the most cases, accounting for 54.17% (39/72); by the education level, the the exposure rate of stall with bachelor degree and below was the highest(90.28%, 65/72); by the professional title level, the exposure rate of staff with primary and intermediate professional titles was relatively high (94.44% , 68/72); by departments, the exposure rate of Blood Donation Service was the highest (81.94%, 59/72), which was twice or even three times than that of other departments; by occupational type, nurses had the highest exposure rate, accounting for 87.5% (63/72); by body parts, hands were the most vulnerable body parts to occupational exposure; by location, the exposure rate on mobile vehicles is four times than that in indoor places; by the number of exposure times, the incidence of one exposure cases accounted for 72.22%(52/72)while multiple exposure was rare by work link, the exposure rate of the sampling link was significantly higher than that of the other links. 【Conclusion】 Blood-borne occupational exposure of staff in blood centers is closely related to gender, age, working years, professional title level, department, occupational type, occurrence place, and body part, and has nothing to do with the education level. More attention should be paid to middle-aged female nurses on the front line of blood donation service, staff with primary or intermediate titles and undergraduate degrees. Otherwise, training and protection should be enhanced, operation methods be standardized, the blood collection environment be improved, and the management, automation and intelligent level of blood collection be promoted.