Abstract Excessive screen-media use among children and adolescents is highly prevalent which increases the risk of being overweight or obese, as well as developing myopia. Therefore, screen time interventions for children and adolescents is of great importance. This review presents a retrospective analysis of foreign studies aimed at reducing screen time for children and adolescents, and summarizes the experience of implementing intervention studies, strategies, and exercise programs in different settings. The findings revealed that foreign studies of screen time in children and adolescents rely on interdisciplinary integration, and the research design of such studies is rigorous and scientific. However, there are still some limitations: Research has failed to account for certain variables (screen media type, age, and gender), and comprehensive evaluations of exercise interventions are lacking. Chinese researchers can formulate scientific and reasonable intervention programs by focusing on the following three factors: advocating multi-department and cross-domain,research cooperation; attaching importance to joint intervention studies based in schools, the community, and family; and strengthening the comprehensiveness of data analytic process, with the ultimate goal of reducing screen time for children and adolescents, as well as promoting their healthy development.

ObjectiveTo investigate the therapeutic effect of ganoderic acid A （GA-A） on a mouse model of concanavalin A （ConA）-induced autoimmune hepatitis （AIH）. MethodsA total of 35 mice were randomly divided into control group （NC group）， model group （ConA group）， and low-， middle-， and high-dose GA-A treatment groups （GA-A-L， GA-A-M， and GA-A-H groups， respectively）， with 7 mice in each group. ConA was injected via the caudal vein of mice to establish a classic mouse model of AIH， and different doses of GA-A were administered via intraperitoneal injection 1 hour later for treatment. Proteomic techniques were used to investigate the protective mechanism of GA-A on hepatocytes， and HL-60 cells were differentiated into dHL-60 neutrophils by all-trans retinoic acid in vitro to validate the mechanism of action of GA-A. Related indicators were measured， including inflammatory markers （the activities of serum alanine aminotransferase ［ALT］ and aspartate aminotransferase ［AST］， HE staining， and inflammation-related genes）， apoptosis markers （TUNEL staining）， neutrophils， and neutrophil extracellular trap （NET） markers （myeloperoxidase ［MPO］， citrullinated histone H3 ［CitH3］， Ly6G， and free double-stranded DNA ［dsDNA］）， and p38 phosphorylation markers. The independent samples t-test was used for comparison of continuous data between two groups； a one-way analysis of variance was used for comparison between multiple groups， and the least significant difference t-test was used for further comparison between two groups. ResultsCompared with the NC group， the ConA group had significant increases in the serum levels of ALT and AST （both P<0.001）， and compared with the ConA group， GA-A treatment significantly reduced the levels of ALT and AST （both P<0.01）. HE staining showed that the mice in the ConA group had significant liver necrosis， while GA-A treatment significantly reduced the area of liver necrosis and the number of TUNEL-positive cells （both P<0.05）. Compared with the ConA group， the GA-A group had significant reductions in the expression levels of the inflammatory factors interleukin-6， tumor necrosis factor-α， and interferon gamma in serum and liver tissue （all P<0.05）. The proteomic analysis showed that GA-A alleviated ConA-induced acute immune liver injury by inhibiting the release of NET and the p38 MAPK pathway. Immunofluorescent staining of mouse liver tissue showed that compared with the ConA group， the GA-A group had significant reductions in the number of MPO-positive neutrophils and the number of cells with positive Ly6G and CitH3 （all P<0.01）. Western Blot and dsDNA testing showed that GA-A significantly inhibited the levels of the NET markers dsDNA and CitH3 and the level of p38 phosphorylation in liver tissue and dHL-60 cells （all P<0.05）. ConclusionGA-A alleviates liver inflammatory response and hepatocyte death by inhibiting the p38 MAPK pathway and the release of NET， thereby alleviating ConA-induced acute immune liver injury. This study provides a theoretical basis for the use of GA-A to treat immune liver injury by regulating neutrophil function.