Objective To construct and validate an interpretable machine learning model integrating contrast-enhanced venous phase CT radiomics and clinical features for preoperative prediction of central lymph node metastasis(CLNM)of papillary thyroid carcinoma(PTC).Methods A case-control study was conducted on 243 histologically confirmed PTC patients.Among them,196 patients from the First Affiliated Hospital of Army Medical University were randomly allocated into a training set(n=137)and an internal validation set(n=59)at a 7:3 ratio,while the left 47 patients from No.958 Hospital of PLA Army were assigned into an external validation set.All participants completed standardized preoperative contrast-enhanced neck CT scanning.Quantitative radiomic features were systematically extracted from venous phase CT images through an open-source big data AI platform.Six machine learning classifiers,eXtreme Gradient Boosting(XGBoost),Support Vector Machine(SVM),Random Forest(RF),Logistic Regression(LR),k-Nearest Neighbors(KNN),and Decision Tree(DT)were implemented to construct clinical-radiomics integration models.The predictive performance was quantitatively assessed through receiver operating characteristic(ROC)curve analysis,with area under the curve(AUC)values calculated for training,internal validation,and external validation sets.Model interpretability was achieved using Shapley additive explanations(SHAP)framework,with particular focus on elucidating feature contributions in the best-performing model.Results The XGBoost model had an AUC value of 0.936(95%CI:0.895～0.976),0.832(95%CI:0.724～0.941),and 0.772(95%CI:0.632～0.912)in training,internal and external validation sets,respectively.SHAP analysis revealed age as the most influential clinical predictor,with younger patients showing higher CLNM risk(OR=0.968,P=0.042).Conclusion Our machine learning-based clinic-radiomic prediction model demonstrates satisfactory performance in predicting CLNM of PTC,providing valuable references for clinical decision-making.

Objective To investigate the predictive value of a nomogram for central lymph node metastasis(CLNM)in patients with papillary thyroid microcarcinoma(PTMC)based on CT features combined with clinical factors.Methods A case-control study was conducted on 256 pathologically confirmed PTMC patients from 2 tertiary hospitals from January 2022 to November 2024.All participants underwent contrast-enhanced neck CT scanning within 2 weeks before surgery and received central lymph node dissection.The 201 patients from the First Affiliated Hospital of Army Medical University were randomized into a training set(n=140)and an internal validation set(n=61)in a 7∶3 ratio.The 55 patients from the Second Affiliated Hospital of Chongqing Medical University were all assigned into an external validation set.Their clinical data and CT features were collected.Univariate and multivariate logistic regression analyses were employed to identify independent predictive factors for CLNM,and then a nomogram model was constructed.Receiver operating characteristic(ROC)curve analysis(area under the curve,AUC),calibration curve,and decision curve analysis(DCA)were performed to evaluate the model performance,discrimination and clinical utility.Results Multivariate logistic regression analysis identified 4 independent CLNM predictors(P<0.05),that is,male(OR=5.991,95%CI:2.209～18.350),tumor size≥0.82 cm(OR=18.880,95%CI:1.803～229.500),capsular involvement(OR=9.805,95%CI:4.015～26.340),and CT-diagnosed lymph node positivity(OR=2.872;95%CI:1.176～7.232).The nomogram achieved an AUC value of 0.859(95%CI:0.796～0.922),0.786(95%CI:0.671～0.901),and 0.783(95%CI:0.648～0.917)in the training and internal and external validation sets,respectively.Calibration curves demonstrated high consistency between predicted and observed probabilities(Hosmer-Lemeshow P>0.05).DCA confirmed net clinical benefits for CLNM before surgical treatment with a threshold probability range of 0.18～0.80.Conclusion Based on sex,tumor size,capsular involvement,and CT-diagnosed lymph node metastasis,our nomogram model effectively predicts CLNM risk in PTMC patients.It can be used as a quantitative tool for personalized surgical planning and shows high clinical applicability.

Objective:To investigate the effect of thoracic X-ray irradiation on the spermatogenesis of adult male mice.Methods:A total of 24 healthy adult male C57BL/6 mice (6-8 weeks old) were randomly divided into radiation group (Radiation) and sham-radiation group (Sham), 12 mice in each group. The area of thoracic irradiation was 1.5 cm× 2 cm, and the dose rate was 3.04 Gy/min, 8 Gy/d for 3 consecutive days, 24 Gy in total. At 7 d and 21 d after thoracic irradiation, the bilateral testes and epididymal tails were stripped and the testicular index was calculated. The morphology of testis was examined by haematoxylin-eosin (HE) staining, then the diameter of seminiferous tubules and the thickness of seminiferous epithelium were measured. The sperms were collected from the bilateral epididymal tails for sperm counting. The level of apoptosis in testis and levels of apoptosis-related proteins were detected by TUNEL and Western blot, respectively.Results:Compared with Sham group, the morphology of testis and epididymis was seriously damaged, the diameter of seminiferous tubules significantly decreased at 21 d after irradiation ( t = 8.93, P < 0.05), and the seminiferous epithelium significantly decreased at 7 d and 21 d after irradiation ( t = 4.24, 12.77, P < 0.05). In addition, the number of sperms significantly decreased ( t = 4.30, 2.98, P < 0.05). The number of TUNEL positive cells in the seminiferous epithelium significantly increased at 7 d and 21 d after irradiation ( t = -2.73, -3.74, P < 0.05). Meanwhile, the level of cleaved Caspase-3 protein significantly increased at 7 d and 21 d after irradiation ( t = -2.96, -2.46, P < 0.05). The concentrations of SCF and GDNF did not change at 7 d after irradiation, but were significantly increased at 21 d after irradiation ( t = -10.46, -5.42, P < 0.05). Conclusions:The thoracic X-ray irradiation could lead to spermatogenesis disorder in male adult mice, and the induction of spermatogenic cell apoptosis and the secretory dysfunction of sertoli cells may be involved.

Objective To explore the effect of carbon nanoparticles-epirubicin suspension on proliferation and apoptosis in human breast cancer MCF-7 cells.Methods MCF-7 cells were cultured with different concentrations of CNP-EPI in vitro.CCK-8 assay was used for determinate inhibition effect of CNP-EPI on the proliferation of MCF-7 cells at different concentration and different time.According to the determination of IC90,5 μg/ml CNP-EPI was selected,and cell morphology and cell apoptosis rates were observed after 24 h.Results The inhibition effect of the CNP-EPI was stronger significantly in CNP-EPI group than in normal control group within 24 h,48 h,72 h when the concentration was from 1 μg/ml to 200 μg/ml (P＜0.01).The inhibition of CNP-EPI on the proliferation of MCF-7 cells was gradually strengthened in a dose-dependent relation within the same time,and the inhibition effect is reduced in the same concentration of drugs with the time extension,but it still has a strong inhibitory effect in 72 h,and the inhibition effect of different concentration of CNP was not obvious on MCF-7 cells.Obvious changes of cell morphology were observed under inverted microscope such as:a lot of dead cells,cell adherent growth poor,cell morphology became round and karyopycnosis etc,in 5 μg/ml CNP-EPI group after 24 h.However,no obvious abnormity of cell norphology was observed in normal control group and corresponding CNP group.Late apoptosis rate was (14.57±2.41) ％,the mortality rate could reach (78.63±-20.55)％ in 5 μg/ml CNP-EPI group after 24 h.The mortality rate and apoptosis rate of cells was higher significantly in CNP-EPI group than in CNP group and normal control group (P＜0.05).Conclusion CNP-EPI can obviously inhibit the proliferation or kill human breast cancer MCF-7cells,and the inhibition effect of CNP-EPI on proliferation of breast cancer cells might be the result of delayed releasing of EPI.