Mental health difficulties and related factors in Chinese children and adolescents during the COVID-19 pandemic: a cross-sectional study Tongtong Li; Chunhao Li; Guoquan Zhang; Naijian Zhang; Jing Li; Qinghan Ren; Wen Li; Zhenshu Li; Guowei Huang; Jing Yan;

Effect of sleep duration on child development in Fortaleza, Northeastern Brazil Shamyr Sulyvan Castro; Marcia Maria Tavares Machado; Luciano Lima Correia; Simone Farias-Antúnez; Pedro Lucas Grangeiro de Sá Barreto Lima; Sophia Costa Vasconcelos; Elisa Rachel Pisani Altafim; Marcia C. Castro;

Mortality in children under five years old in Brazil: evolution from 2017 to 2020 and the influence of COVID-19 in 2020 Erly C. Moura; Juan Cortez-Escalante; Rodrigo T.S. Lima; Fabrício V. Cavalcante; Layana C. Alves; Leonor M.P. Santos;