Objective To evaluate the degree of invasion of placental implantation by quantitative delin-eation of MRI placental bed abnormal hyperplasia vessels by 3D-Slicer software.Methods Fifty-seven pa-tients with placenta implantation requiring MRI in Quanzhou Maternal and Child Health Hospital from July 2020 to December 2023 were retrospectively collected and divided into the penetrating placenta implantation group(n=11)and the non-penetrating placenta implantation group(n=46),and the differences of MRI mor-phological signs between the two groups were analyzed.Among them,37 patients with placental bed xenogenic vessels scanned by MRI were screened and there were 11 cases in the penetrating placental implantation group and 26 cases in the non-penetrating placental implantation group.3D-Slicer software was used to delineate the surface area and volume of placental bed xenogenic vessels,the differences between the two groups were ana-lyzed.Results There were significant differences in the surface area and volume of xenogenic blood vessels in placental bed between the two groups(P＜0.05).The large surface area of xenogenic vessels in the placental bed was an independent risk factor for penetrative placental implantation,and the predicted area under the curve(AUC)of penetrative placental implantation was 0.927.When the surface area of the placental bed was 1 079.25 mm2,the sensitivity was 81.8%and the specificity was 88.5%.Conclusion According to 3D-Slicer soft-ware,the diagnostic efficacy of placental bed allogenic blood vessel surface area for penetrating placental implanta-tion is high.The larger the allogenic blood vessel surface area is,the deeper the placental invasion of uterus is.

Objective:To investigate the current status and challenges of pediatric life support training in China and provide references for improving training quality.Methods:A cross-sectional study was conducted to collect data from pediatric life support training centers across the country，covering basic institutional information，training capacity and training faculty，training program funding，as well as existing challenges and issues.The domestic registry of training centers in 2023 was obtained through the American Heart Association's online platform.After contacting and verifying each center，an online questionnaire was distributed，and the aggregated data were statistically analyzed.Results:A total of 42 institutions participated in the survey，including 19 children's hospitals，14 general hospitals，6 maternal and child health hospitals，2 women and children’s hospitals，and 1 training institution.The distribution of training centers showed a concentration in coastal areas，with the top three provinces/municipalities being Guangdong（7/42，16.7%），Zhejiang（6/42，14.3%），and Shanghai（4/42，9.5%）.As of December 31 2023，the 42 institutions had an annual basic life support（BLS）training volume of 8 587 individuals，the median was 120 (100,200)，and an annual pediatric advanced life support（PALS）training volume of 2 448 individuals，the median was 30 (20,50).Among the 42 institutions，there were 598 BLS instructors and 306 PALS instructors.Among the surveyed institutions，24（24/42，57.1%）reported BLS instructor teams comprising fewer than 10 members，and 33（33/42，78.6%）reported PALS instructor teams comprising fewer than 10.Only 7 centers(7/42,16.7%）reported having dedicated funding support.The top three challenges were：training sessions occupying instructors’personal time（27/42，64.3%），low instructor compensation（16/42，38.1%），and issues with the data submission system（16/42，38.1%）.Conclusion:Pediatric life support training centers in China are primarily children’s hospitals，with a geographical concentration in coastal areas，which is also reflected in the distribution of training scale and instructor resources.Most centers have relatively small training scales and limited instructor capacity，with many instructors conducting training during their personal time.These issues may hinder the implementation and effectiveness of training programs.

Objective:To investigate the current status and challenges of pediatric life support training in China and provide references for improving training quality.Methods:A cross-sectional study was conducted to collect data from pediatric life support training centers across the country，covering basic institutional information，training capacity and training faculty，training program funding，as well as existing challenges and issues.The domestic registry of training centers in 2023 was obtained through the American Heart Association's online platform.After contacting and verifying each center，an online questionnaire was distributed，and the aggregated data were statistically analyzed.Results:A total of 42 institutions participated in the survey，including 19 children's hospitals，14 general hospitals，6 maternal and child health hospitals，2 women and children’s hospitals，and 1 training institution.The distribution of training centers showed a concentration in coastal areas，with the top three provinces/municipalities being Guangdong（7/42，16.7%），Zhejiang（6/42，14.3%），and Shanghai（4/42，9.5%）.As of December 31 2023，the 42 institutions had an annual basic life support（BLS）training volume of 8 587 individuals，the median was 120 (100,200)，and an annual pediatric advanced life support（PALS）training volume of 2 448 individuals，the median was 30 (20,50).Among the 42 institutions，there were 598 BLS instructors and 306 PALS instructors.Among the surveyed institutions，24（24/42，57.1%）reported BLS instructor teams comprising fewer than 10 members，and 33（33/42，78.6%）reported PALS instructor teams comprising fewer than 10.Only 7 centers(7/42,16.7%）reported having dedicated funding support.The top three challenges were：training sessions occupying instructors’personal time（27/42，64.3%），low instructor compensation（16/42，38.1%），and issues with the data submission system（16/42，38.1%）.Conclusion:Pediatric life support training centers in China are primarily children’s hospitals，with a geographical concentration in coastal areas，which is also reflected in the distribution of training scale and instructor resources.Most centers have relatively small training scales and limited instructor capacity，with many instructors conducting training during their personal time.These issues may hinder the implementation and effectiveness of training programs.

Objective To investigate the application effect of case-based teaching versus traditional teaching in the optional course of maternal and child nutrition for medical undergraduates.Methods The students who completed the course through the traditional teaching method in 2016 were enrolled as control group,and those who completed the course through the case-based teaching method in 2017 were enrolled as experimental group.In the process of teaching,the teachers in the experimental group needed to write cases,prepare lessons collectively,give guidance and inspiration,and summarize after class.During the learning process,the students in the experimental group needed to collect information before class and perform role play,group discussion,and intergroup communication about the case during class.After the course ended,a questionnaire for nutrition during pregnancy preparation,pregnancy,and lactation,breastfeeding,and complementary feeding was developed for assessment.With sex and grade as related factors,SPSS 18.0 was used for the chi-square test of two sample rates according to knowledge points,and the correct rate of each item was analyzed.Results A total of 107 valid questionnaires were collected from the control group,and 109 valid questionnaires were collected from the experimental group.For the questions on the knowledge of maternal and child nutrition,the experimental group had slightly higher correct rates than the control group (all P＞0.05).For the questions on the comprehension and practical application of the knowledge of maternal and child nutrition,the experimental group had significantly higher correct rates than the control group (all P＜0.05).Further stratified analysis based on sex and grade showed that the experimental group had higher correct rates than the control group.Conclusion Compared with traditional teaching,case-based teaching may not have advantages in enhancing students' memorizing ability,but it can make it easier for students to understand the theoretical knowledge of matemal and child nutrition and master the practical application of such knowledge.

BACKGROUND: Mesenchymal stem cells attract extensive attention because of good biological characteristics and broad prospects, but the cells gradually show the characteristics of the aging with the increase of individual age or incubation time in vitro. Nonhuman primates have similar biological characteristics with human being, and have unique advantage in the animal model and disease treatment research.OBJECTIVE: To analyze the difference in proliferation and differentiation of bone marrow mesenchymal stem cells from macaques at different ages and to explore the effect of age on bone marrow mesenchymal stem cells and the possible mechanism.METHODS: Bone marrow samples from male macaques aged < 3 years and over 20 years were collected through bone marrow puncture, and divided into young group and elder group, with three macaques in each group. Then, bone marrow mesenchymal stem cells were isolated and cultured in vitro, and the morphological changes, proliferation and differentiation ability were observed. Age-related beta-galactosidase staining was performed, and protein microarray and ELISA were used to detect cytokine levels.RESULTS AND CONCLUSION: With age, the proliferation and differentiation of bone marrow mesenchymal stem cells from the elder macaques were reduced significantly, and the number of senescent cells increased significantly; the levels of interleukin-1b, interleukin-4, interleukin-6, tumor necrosis factor α and vascular endothelial growth factor were elevated obviously, the levels of heparin-binding basic fibroblast growth factor and placental growth factor were reduced. These findings indicate that the body's aging lead to the reduction in the proliferation, differentiation and cytokine secretion of bone marrow mesenchymal stem cells.

AIM:To investigate the potential of hematopoietic stem cells(HSCs)derived from mouse embryonic stem cells(ESCs)to reconstruct hematopoiesis in vivo.METHODS:Using a three-step method,a mice embryonic stem cell line,E14.1 was induced into hematopoietic stem cells.The cell markers with CD34+/Sca-1+ were identified by flow cytometry analysis,then HSCs(1?109 cells/L)from third-step were injected into SCID mice for observing teratoma formation.To validate function of HSCs,colonogenic cell assay was conducted and the hematopoiesis in lethally irradiated mice was reconstituted.RESULTS:The method of three-step differentiation,combined to use more hematopoietic stimulating factor promoted the E14.1 cell differentiation into HSCs with highest percent of CD34+/Sca-1+ cells(as high as 58.64%?4.20%)with more CFU-E,CFU-GM and CFU-GEMM populations.The cells showed the character of hematopoietic progenitors by Wright-Giemsa staining.Positive selected CD34+/Sca-1+ cells by magnetic sorting from third-step differentiation were transplanted into 7 lethally irradiated female mice while predominant hematopoietic reconstitution were observed in 10 d after transplantation,with 71.4%(5/7)successful engraftment rate.Three recipients showed that the cell population of the peripheral blood leukocytes,red blood cells and hemoglobin approached to normal index at 40 d after transplantation,but followed relative slow renew in platelet count.Survival rate in transplant group was 43%,compared to 100% mortality in control mice.Karyotyping assays confirmed the female mice with XY.CONCLUSION:The three-step differentiation and the culture conditions described here support the differentiation of mouse ESCs into HSCs.HSCs derived from mouse ESCs can reconstruct hematopoiesis.