ABSTRACT
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
Senescence is an internally systematized degeneration process leading to death in plants. Leaf yellowing, oneof the most prominent features of plant aging may lead to reduced crop yields. The molecular mechanism ofresponses to senescence in soybean leaves is not completely clear. In our research, two soybean varieties wereselected with different stay-green traits: stay-green variety (BN106) and non-stay-green variety (KF14). RNAsamples extracted from the leaves of two varieties were sequenced and compared using high-throughputsequencing. Six key enzyme genes in chlorophyll degradation pathways were studied to analyze the changes intheir expression at seedling, flowering and maturation stage. Meanwhile, the construction of the genetictransformation process had been constructed to identify the function of putative gene by RNA-interference. Atotal of 4329 DEGs were involved in 52 functional groups and 254 KEGG pathways. Twelve genes encodingsenescence-associated and inducible chloroplast stay-green protein showed significant differential expression.MDCase and PAO have a significant expression in BN106 that may be the key factors affecting the maintenance of green characteristics. In addition, the function of GmSGRs has been identified by genetic transformation. The loss of GmSGRs may cause soybean seeds to change from yellow to green. In summary, ourresults revealed fundamental information about the molecular mechanism of aging in soybeans with differentstay-green characteristics. The work of genetic transformation lays a foundation for putative gene functionstudies that could contribute to postpone aging in soybeans
ABSTRACT
Doxorubicin (DOX) was conjugated to a single-chain variable fragment (scFv) against human midkine (MK), and the conjugate (scFv-DOX) was used to target the chemotherapeutic agent to a mouse solid tumor model in which the tumor cells expressed high levels of human MK. The His-tagged recombinant scFv was expressed in bacteria, purified by metal affinity chromatography, and then conjugated to DOX using oxidative dextran (Dex) as a linker. The molecular formula of this immunoconjugate was scFv(Dex)1.3(DOX)20. In vitro apoptosis assays showed that the scFv-DOX conjugate was more cytotoxic against MK-transfected human adenocarcinoma cells (BGC823-MK) than untransfected cells (55.3 ± 2.4 vs 22.4 ± 3.8 percent) for three independent experiments. Nude mice bearing BGC823-MK solid tumors received scFv-DOX or equivalent doses of scFv + DOX for 2 weeks and tumor growth was more effectively inhibited by the scFv-DOX conjugate than by scFv + DOX (51.83 percent inhibition vs 40.81 percent). Histological analysis of the tumor tissues revealed that the highest levels of DOX accumulated in tumors from mice treated with scFv-DOX and this resulted in more extensive tumor cell death than in animals treated with the equivalent dose of scFv + DOX. These results show that the scFv-DOX conjugate effectively inhibited tumor growth in vivo and suggest that antigen-specific scFv may be competent drug-carriers.