Resumo O objetivo do estudo foi investigar os efeitos da atividade física (AF) na variabilidade da frequência cardíaca (VFC) em crianças e adolescentes. Realizamos uma pesquisa nas bases Web of Science, PubMed, ScienceDirect, Springer-Link e EBSCO-host. A Escala Newcastle-Ottawa revisada foi utilizada para avaliar o risco de enviesamento. Um total de 21 estudos foi incluído. De forma geral, foram encontradas associações de médio porte entre AF e baixa frequência e alta frequência em crianças e adolescentes. O alto nível de AF teve um desvio padrão significativamente maior dos intervalos e raiz da média da soma dos quadrados de diferenças entre os intervalos RR adjacentes em crianças e adolescentes. Os efeitos de AF sobre VFC foram consistentes em crianças e adolescentes. Nossa revisão sistemática e meta-análise revelou que AF e VFC em crianças e adolescentes são de médio porte. Promover a participação de crianças e adolescentes em atividade física de moderada à vigorosa (AFMV) aumentará a atividade nervosa parassimpática e diminuirá a atividade nervosa simpática. Nossas descobertas apoiam a motivação de crianças e adolescentes a se envolverem mais na AFMV em suas vidas diárias para melhorar o funcionamento do sistema nervoso autônomo e promover a segurança cardiovascular.

Abstract The aim of the study was to investigate the effects of physical activity (PA) on heart rate variability (HRV) in children and adolescents. We conducted a research of Web of Science, PubMed, ScienceDirect, Springer-Link and EBSCO-host. The revised Newcastle-Ottawa Scale was used in an investigative analysis to assess bias risk. A total of 21 studies were included. Overall, medium-sized associations were found between PA and low frequency and high frequency in children and adolescents. High PA level had significantly higher standard deviation of RR intervals and root of the mean of the sum of the squares of differences between adjacent RR intervals in children and adolescents. The effects of PA on HRV were consistent in children and adolescents. Our systematic review and meta-analysis revealed medium-sized between PA and HRV in children and adolescents. Promoting children’s and adolescents’ participation in moderate-to-vigorous physical activity (MVPA) will increase parasympathetic nerve activity and decreased sympathetic nerve activity. Our findings support motivating children and adolescents to engage in more MVPA in their daily lives to improve autonomic nervous system function and promote cardiovascular safety.

Resumo O objetivo do estudo foi investigar os efeitos da atividade física (AF) na variabilidade da frequência cardíaca (VFC) em crianças e adolescentes. Realizamos uma pesquisa nas bases Web of Science, PubMed, ScienceDirect, Springer-Link e EBSCO-host. A Escala Newcastle-Ottawa revisada foi utilizada para avaliar o risco de enviesamento. Um total de 21 estudos foi incluído. De forma geral, foram encontradas associações de médio porte entre AF e baixa frequência e alta frequência em crianças e adolescentes. O alto nível de AF teve um desvio padrão significativamente maior dos intervalos e raiz da média da soma dos quadrados de diferenças entre os intervalos RR adjacentes em crianças e adolescentes. Os efeitos de AF sobre VFC foram consistentes em crianças e adolescentes. Nossa revisão sistemática e meta-análise revelou que AF e VFC em crianças e adolescentes são de médio porte. Promover a participação de crianças e adolescentes em atividade física de moderada à vigorosa (AFMV) aumentará a atividade nervosa parassimpática e diminuirá a atividade nervosa simpática. Nossas descobertas apoiam a motivação de crianças e adolescentes a se envolverem mais na AFMV em suas vidas diárias para melhorar o funcionamento do sistema nervoso autônomo e promover a segurança cardiovascular.

Abstract The aim of the study was to investigate the effects of physical activity (PA) on heart rate variability (HRV) in children and adolescents. We conducted a research of Web of Science, PubMed, ScienceDirect, Springer-Link and EBSCO-host. The revised Newcastle-Ottawa Scale was used in an investigative analysis to assess bias risk. A total of 21 studies were included. Overall, medium-sized associations were found between PA and low frequency and high frequency in children and adolescents. High PA level had significantly higher standard deviation of RR intervals and root of the mean of the sum of the squares of differences between adjacent RR intervals in children and adolescents. The effects of PA on HRV were consistent in children and adolescents. Our systematic review and meta-analysis revealed medium-sized between PA and HRV in children and adolescents. Promoting children’s and adolescents’ participation in moderate-to-vigorous physical activity (MVPA) will increase parasympathetic nerve activity and decreased sympathetic nerve activity. Our findings support motivating children and adolescents to engage in more MVPA in their daily lives to improve autonomic nervous system function and promote cardiovascular safety.

Abstract In order to study the mechanism of arabinoxylan (AX) delaying the aging of steamed bread, the effects of AX on gelatinization, texture and starch crystallinity of steamed bread were analyzed. The results were as follows: as the storage time of steamed bread extended, the hardness and chewiness of steamed bread decreased successively in the control group, water extract AX group and enzyme extract AX group. The gelatinization of flour was decreased by both water and WEAX and EEAX, and a significant effect were observed in EEAX group. In the storage process of steamed bread, AX could inhibit the crystallinity rate of amylopectin in the freeze-dried powder of steamed bread, and the overall change range of ΔH was lower than that of control. The x-diffraction results showed that adding AX could reduce the crystallinity of steamed bread. Hence, it delays the retrogradation process and thus delay the aging of steamed bread. These results suggest that Arabinoxylan can be used as a novel additive in CSB industry, not only for the nutritional value, but also the anti-staling effect.

pH-Zone-refining counter-current chromatography (PZRCCC) was successfully used for preparative separation isoquinoline alkaloids from Phellodendri Cortex. Two target compounds of berberine and palmatine were completely resolved by a two-phase solvent system chloroform/methanol/water (4:2:2, v/v), with 10 mmol L-1 HCl in upper stationary phase and 10 mmol L-1 TEA in lower organic phase. From 2.0 g of the crude alkaloids, palmatine (448 mg, 95.1%) and berberine (159 mg, 95.4%) were obtained in one-step PZRCCC separation. The chemical structures were identified by ESI-MS and NMR data. The results indicated that PZRCCC separation is an excellent preparative separation method for isoquinoline alkaloids from Phellodendri Cortex.