ObjectiveTo evaluate the efficacy and safety of endoscopic submucosal dissection (ESD) for precancerous lesions and early cancer at gastroesophageal junction (GEJ) by comparing endoscopic mucosal resection (EMR) with ESD.MethodsData of patients with GEJ precancerous lesions or early cancer,who received EMR ( n =51 ) or ESD ( n =28) were reviewed to compared the en bloc resection rate,R0 resection rate,operation time,complication and recurrence rate between 2 methods.ResultsEn blcc resection and R0 resection rates of ESD group (92.9％,78.6％ respectively) were significantly higher than those of EMR group (45.1％,43.1％ respectively).Local recurrence rate in ESD group (3.6％,1/28) was significantly lower than that of EMR group ( 19.6％ ).Complications including perforation,delayed hemorrhage,stricture were not significantly different between EMR and ESD groups.Mean operation time of ESD group (64.3 ±27.1 min) was significantly longer than that of EMR group (27.6 ± 14.1 min)(P ＜0.05).ConclusionESD,with a higher cure rate and en bloc rate and a lower local recurrence rate,is superior to EMR for precancerous lesions and early cancer at GEJ.

Objective: To determine the nutritional status and associated factors of vitamin D in primary and middle school students in Shandong Province, so as to provide reference for developing targeted vitamin deficiency interventions. Methods: From January to September 2021, using multi stage stratified random sampling, physical examinations and laboratory tests were carried out among 3 539 primary and middle school students in Shandong Province. Associated factors of vitamin D were analyzed by Logsitc regression analysis. Results: The average vitamin D level among primary and middle school students was (17.56±6.65) ng/mL, while the deficiency and severe deficiency rate was 67.4%. Multivariate Logistic regression analysis showed that girls ( OR =1.95), students in junior high school ( OR =2.14) and senior high school ( OR =2.36) were at higher risk of vitamin D deficiency and severe deficiency ( P <0.05). Students from coastal areas ( OR =0.54), physical examination in summer and autumn ( OR = 0.74 ), and 35 g of egg intake per day ( OR =0.53), and with outdoor activity time greater than 60-120 min and >120 min ( OR =0.63, 0.48) had lower risk of vitamin D deficiency ( P <0.05). Conclusions The nutritional status of vitamin D among elementary and secondary school students in Shandong Province warrants further attention. Intervention measures such as nutritional education, healthy diet and prolonging outdoor activities should be promoted in primary and middle school students.