Objective To observe the value of MR intravoxel incoherent motion(IVIM)for analyzing placental microcirculation and microstructures in plateau area of late pregnancy induced hypertension(PIH)and normal middle and late pregnancy.Methods Totally 26 cases of PIH in late-trimester of pregnancy(group A)and 46 normal pregnant women(including 18 normal middle-trimester[group B]and 28 normal late-trimester[group C])in plateau area were retrospectively analyzed.The perfusion fraction(f),true diffusion coefficient(D)and pseudo-diffusion coefficient(D*)values of the entire placenta and the fetal side,maternal side and central region of placenta were obtained based on MR IVIM data,intra-and inter-group comparisons were conducted.Pearson correlation analysis was used to explore the relationships of placental IVIM parameters and maternal age,gestational age,estimated fetal weight(EFW)and neonatal birth weight.Results Except for f value of placental maternal side was higher than of fetal side in group C(P＜0.05),no significant difference was found in pairwise comparisons of IVIM parameters between different placental regions within each group(all P＞0.05).f value of the entire placenta and its fetal side,as well as D value of the entire placenta and its maternal side in group A were all higher than those in group C(all adjusted P＜0.05).The f and D* values of the entire placenta,f,D and D*values of its maternal side,as well as f and D* values of the fetal side in group C were all higher than those in group B(all adjusted P＜0.05).In group C,f value of placental maternal side was negatively correlated with both gestational age and EFW(r=-0.441,-0.579,both P＜0.01).Conclusion MR IVIM could be used to non-invasively assess placental microcirculation and microstructures in plateau area of late PIH and normal middle and late pregnancy women.

Objective:To screen the optimal machine learning model for predicting the recurrence condition of hepatocellular carcinoma (HCC) at different time points post-surgery, based on the cutoff value of the Ki67 positive proliferation index condition calculated from recurrence-free survival and combined with various clinical features.Methods:retrospective study included initially treated patients with solitary HCC who underwent radical surgery at the Fifth Medical Center of the PLA General Hospital from January 2013 to March 2023. Data included general clinical data, preoperative laboratory parameters, and surgical pathology information about the subjects. The postoperative recurrence status was assessed by querying the medical record system or by telephone follow-up. The Ki67 positive index cutoff value was determined by the X-tile software based on the patient's recurrence-free survival status and time analysis. Survival rates were calculated using the Kaplan-Meier method, and survival curves were plotted. The study population was randomly divided into training and testing groups in a 7:3 ratio using a computer-generated random number method. The minimum redundancy maximum relevance (mRMR) method was used for feature variable selection. Predictive models for postoperative HCC recurrence conditions in patients with HCC were constructed using random forest, support vector machine, logistic regression, and gradient boosting decision tree machine learning algorithms. Inter-group comparisons for continuous data were performed using the t-test or Mann-Whitney U test. Inter-group comparisons of enumeration data were performed using the Pearson χ2 test, continuity-corrected χ2 test, or Fisher's exact test. Results:The cutoff values for the Ki67 positivity index were 0.3 and 0.5 in 510 cases, with a follow-up time ranging from 1.2 to 11.4 years (median: 6.2 years). The recurrence-free survival time was between 1 and 135 months (median: 32 months), with recurrence-free survival rates post-surgery at 1, 2, 3, and 5 years were 87.5%, 77.1%, 61.2%, and 54.5%, respectively. The top five variables predicted HCC recurrence and non-recurrence conditions following surgical follow-up at 6 months, 1 year, 2 years, and beyond 2 years, in accordance with information obtained by the mRMR screen out. The Ki67 positivity index screened a successfully constructed machine learning model to predict HCC recurrence and non-recurrence conditions following surgical follow-up at 6 months, 1 year, 2 years, and beyond 2 years. The machine learning model based on the gradient boosting decision tree algorithm had the best prediction performance among them (areas under the receiver operating characteristic curves for predicting HCC recurrence within six months in the training and validation sets were 0.996 and 0.946, and accuracies were 0.972 and 0.935, respectively).Conclusion:A machine learning model was successfully constructed using the Ki67 positivity index combined with four readily available clinical features to predict HCC recurrence. The machine learning model based on the gradient boosting decision tree algorithm demonstrated the best performance in terms of predicting HCC recurrence within six months after surgery.

Objective To observe the value of MR intravoxel incoherent motion(IVIM)for analyzing placental microcirculation and microstructures in plateau area of late pregnancy induced hypertension(PIH)and normal middle and late pregnancy.Methods Totally 26 cases of PIH in late-trimester of pregnancy(group A)and 46 normal pregnant women(including 18 normal middle-trimester[group B]and 28 normal late-trimester[group C])in plateau area were retrospectively analyzed.The perfusion fraction(f),true diffusion coefficient(D)and pseudo-diffusion coefficient(D*)values of the entire placenta and the fetal side,maternal side and central region of placenta were obtained based on MR IVIM data,intra-and inter-group comparisons were conducted.Pearson correlation analysis was used to explore the relationships of placental IVIM parameters and maternal age,gestational age,estimated fetal weight(EFW)and neonatal birth weight.Results Except for f value of placental maternal side was higher than of fetal side in group C(P＜0.05),no significant difference was found in pairwise comparisons of IVIM parameters between different placental regions within each group(all P＞0.05).f value of the entire placenta and its fetal side,as well as D value of the entire placenta and its maternal side in group A were all higher than those in group C(all adjusted P＜0.05).The f and D* values of the entire placenta,f,D and D*values of its maternal side,as well as f and D* values of the fetal side in group C were all higher than those in group B(all adjusted P＜0.05).In group C,f value of placental maternal side was negatively correlated with both gestational age and EFW(r=-0.441,-0.579,both P＜0.01).Conclusion MR IVIM could be used to non-invasively assess placental microcirculation and microstructures in plateau area of late PIH and normal middle and late pregnancy women.

Objective:To screen the optimal machine learning model for predicting the recurrence condition of hepatocellular carcinoma (HCC) at different time points post-surgery, based on the cutoff value of the Ki67 positive proliferation index condition calculated from recurrence-free survival and combined with various clinical features.Methods:retrospective study included initially treated patients with solitary HCC who underwent radical surgery at the Fifth Medical Center of the PLA General Hospital from January 2013 to March 2023. Data included general clinical data, preoperative laboratory parameters, and surgical pathology information about the subjects. The postoperative recurrence status was assessed by querying the medical record system or by telephone follow-up. The Ki67 positive index cutoff value was determined by the X-tile software based on the patient's recurrence-free survival status and time analysis. Survival rates were calculated using the Kaplan-Meier method, and survival curves were plotted. The study population was randomly divided into training and testing groups in a 7:3 ratio using a computer-generated random number method. The minimum redundancy maximum relevance (mRMR) method was used for feature variable selection. Predictive models for postoperative HCC recurrence conditions in patients with HCC were constructed using random forest, support vector machine, logistic regression, and gradient boosting decision tree machine learning algorithms. Inter-group comparisons for continuous data were performed using the t-test or Mann-Whitney U test. Inter-group comparisons of enumeration data were performed using the Pearson χ2 test, continuity-corrected χ2 test, or Fisher's exact test. Results:The cutoff values for the Ki67 positivity index were 0.3 and 0.5 in 510 cases, with a follow-up time ranging from 1.2 to 11.4 years (median: 6.2 years). The recurrence-free survival time was between 1 and 135 months (median: 32 months), with recurrence-free survival rates post-surgery at 1, 2, 3, and 5 years were 87.5%, 77.1%, 61.2%, and 54.5%, respectively. The top five variables predicted HCC recurrence and non-recurrence conditions following surgical follow-up at 6 months, 1 year, 2 years, and beyond 2 years, in accordance with information obtained by the mRMR screen out. The Ki67 positivity index screened a successfully constructed machine learning model to predict HCC recurrence and non-recurrence conditions following surgical follow-up at 6 months, 1 year, 2 years, and beyond 2 years. The machine learning model based on the gradient boosting decision tree algorithm had the best prediction performance among them (areas under the receiver operating characteristic curves for predicting HCC recurrence within six months in the training and validation sets were 0.996 and 0.946, and accuracies were 0.972 and 0.935, respectively).Conclusion:A machine learning model was successfully constructed using the Ki67 positivity index combined with four readily available clinical features to predict HCC recurrence. The machine learning model based on the gradient boosting decision tree algorithm demonstrated the best performance in terms of predicting HCC recurrence within six months after surgery.

Objective To study placental microcirculation and microstructure of pregnant women with pregnancy-induced hyper-tension by using MRI intravoxel incoherent motion(IVIM)at plateau area.Methods A retrospective analysis was performed on 22 healthy pregnant women at third trimester with single birth and 20 pregnant women with pregnancy-induced hypertension.All subjects underwent ultrasound,routine MRI and IVIM examination.The D,D*,f values of the whole placental and various parts of the placental,estimated fetal weight(EFW)and postnatal weight were measured and recorded.The differences of two groups data were analyzed by independent sample t test or one-way analysis of variance,and then multiple comparisons of placental quantitative parameters between the two groups were analyzed by Bonferroni method.Results The fetal side and whole placental f values in healthy pregnant women at third trimester were higher than pregnancy-induced hypertension(P＜0.05),the maternal side and whole placental D values in healthy pregnant women at third trimester were higher than pregnancy-induced hypertension(P＜0.05),the EFW and fetal birth weight in healthy pregnant women at third trimester were higher than pregnancy-induced hypertension(P＜0.05).Conclusion IVIM can effectively evaluate placental blood flow microcirculation and microstructure with pregnancy-induced hypertension at plateau area,and provide a new proof for clinical evaluation of placental structure and function changes.

Objective To investigate the characteristics and differences of gastric flora in chronic non-atrophic gastritis and chronic atrophic gastritis associated with Helicobacter pylori (H. pylori). Methods A prospective study was adopted, and 24 patients with chronic gastritis caused by H. pylori infection were divided into chronic non-atrophic gastritis group (n=18) and chronic atrophic gastritis group (n=6). Characteristics of gastric mucosal flora in both groups were determined, and Alpha and Beta diversity analyses and species correlation analysis were performed. Results The gastric flora in both groups were mainly consisted of Proteobacteria, Bacteroidetes, Firmicutes, Actinobacteria, and Fusobacteria. Significant differences in species diversity and abundance were observed between the two groups (ANOSIM analysis, P=0.046). Fusobacterium (P=0.023), Leptotrichia (P=0.047), Prevotella (P=0.016), Sphingomonas (P=0.042), and Treponema (P=0.006) were significantly enriched in the chronic atrophic gastritis group, and H. pylori showed a decreasing trend (P=0.218). Some species of gastric mucosal flora showed negative correlations with H. pylori, and the number of species negatively associated with H. pylori in the gastric mucosal flora of chronic atrophic gastritis was significantly reduced. Conclusion In the gastric mucosa of chronic atrophic gastritis, the Fusobacterium, Leptotrichia, Prevotella, Sphingomonas, and Treponema are significantly enriched and associated with the progression of chronic gastritis.