Titin: structure, isoforms and functional regulation / 生理学报

Titin, the largest known protein in the body expressed in three isoforms (N2A, N2BA and N2B), is essential for muscle structure, force generation, conduction and regulation. Since the 1950s, muscle contraction mechanisms have been explained by the sliding filament theory involving thin and thick muscle filaments, while the contribution of cytoskeleton in force generation and conduction was ignored. With the discovery of insoluble protein residues and large molecular weight proteins in muscle fibers, the third myofilament, titin, has been identified and attracted a lot of interests. The development of single molecule mechanics and gene sequencing technology further contributed to the extensive studies on the arrangement, structure, elastic properties and components of titin in sarcomere. Therefore, this paper reviews the structure, isforms classification, elastic function and regulatory factors of titin, to provide better understanding of titin.

Meta-analysis of the influence of physical activity on executive function and academic performance of school-age children / 中国学校卫生

Objective@#To conduct a meta-analysis of relevant literature and systematically evaluate the effects of physical activity on the executive function and academic performance of school-age children (6-12 years old) in the past 20 years, and to provide a new perspective for future interventions to promote physical activity of school-age children and school health decisions.@*Methods@#Using systematic reviews and meta-analysis methods, papers regarding the eflect of phyical activity on executive function and academic performance among school-age children physical activities published during the period from January 1, 2000 to December 31, 2019 were retrieved in five databases including PubMed, Web of Science, Medline, Eric and SPORTDiscus. The English retrieval words were “child*” OR “pediatr*” OR “paediatr*” OR “teen*” OR “preadolescen*” OR “preadolescen*” OR “youth” OR (“primary” OR “elementary” AND “school*”) AND “control group” OR “control condition” OR “randomi*” OR “cross-over” AND “motor activity” OR “exercise” OR “physical fitness” OR “physical endurance” AND “executive function” OR “Inhibition (Psychology)” OR “problem solving” OR “cognition” AND “academic*” OR “school*” OR “education*” AND “achievement*” OR “performance*” OR “abilit*” OR “skill*” OR “competence”.@*Results@#A total of 23 relevant literatures were included and evaluated. Longitudinal physical activity had a positive effect on executive function (Hedges’g=0.24, 95%CI=0.09-0.39) and academic performance (Hedges’g=0.26, 95%CI=0.02-0.49).@*Conclusion@#The study found that physical activity has a positive effect on the executive function and academic performance of school-age children. Interventions for promoting regular physical activity within a few weeks will achieve the greatest effect.