Effects of physical activities on cognitive flexibility of Chinese children and adolescents: a Meta analysis / 中国学校卫生

Objective@#The purpose of this paper is to systematically review the impact of physical activities on cognitive flexibility of children and adolescents in China, and to provide evidence based evidence for relevant research on improving cognitive flexibility of children and adolescents by using physical activities.@*Methods@#CNKI, VIP, Wanfang Data, Web of Science, SPORTDiscus, PubMed, Springer link and Science Direct database were searched. The time span of 40 articles collected in this study was from the establishment of the database to December 31, 2020.@*Results@#A total of 3 262 research samples were included in 40 articles, including 1 674 in the experimental group and 1 588 in the control group. Meta analysis showed that the total effect WMD value of literature was 121.11, Z =12.37, 95% CI =101.91-140.30 ( P <0.01); the sub group of school age children included 32 literatures, and the combined effect WMD value was 126.05, Z =10.42, 95% CI =102.34-149.76 ( P <0.01); the sub group of adolescents included 8 literatures, the combined effect WMD value was 104.00, Z =9.72, 95% CI =83.02-124.98 ( P <0.01). Compared with the control group, physical activity had a significant positive effect on the cognitive flexibility of Chinese children and adolescents. The source of heterogeneity in school age children group was tested by meta regression method. The results showed that the type of children t =12.77, 95% CI =28.79-39.74( P <0.01) was the primary source of heterogeneity in Meta analysis. The results of egger regression analysis showed that t =0.47, 95% CI =-1.48-2.37( P =0.64), and there was no publication bias.@*Conclusion@#Adolescence is the sensitive period for development of cognitive flexibility, and physical activities have a significant positive impact on the cognitive flexibility of children and adolescents.

Effects of different intensity physical activities on working memory in children and adolescents: a Meta-analysis / 中国学校卫生

Objective@#To explore the effects of different intensity physical activity on the working memory among children and adolescents, so as to provide evidence-based basis for school mental health and physical education.@*Methods@#Seven databases were searched by using keywords including "moderate intensity sports" "high intensity sports" "working memory" "cognitive function" "moderate physical activity" "vigorous physical activity" "moderate intensity exercise" "high intensity exercise" "acute physical activity" "chronic physical activity". The retrieval time was August 2019. The PICOS model was used to screen the literature. A total of 40 related literatures were included. The Jadad score of the literature was good, and the random effect model was used for meta-analysis.@*Results@#The analysis results showed that the effect of moderate intensity physical activity on children’s values of WMD=136.98, Z=21.77, 95%CI=124.65-149.31; The effect of the youth group WMD=95.78, Z=9.08, 95%CI=75.11-116.46. The total effect value of WMD=126.17, Z=23.35, 95%CI=115.58-136.76(P<0.01). The effect of high intensity physical activity on children’s values of WMD=-6.05, Z=0.38, 95%CI=-37.15-25.06(P=0.70). The effect of the youth group WMD=8.51, Z=0.60, 95%CI=-19.12-36.13(P=0.55). The total effect value of WMD=2.09, Z=0.20, 95%CI=-18.57-22.74(P=0.84).@*Conclusion@#Moderate intensity physical activity can improve the working memory of children and adolescents. High intensity physical activities have no positive influence on working memory of children and adolescents. When considering sports activities to improve working memory of children and adolescents, moderate intensity exercise is recommended.

In vitro culture and characterization of alveolar bone osteoblasts isolated from type 2 diabetics

In order to understand the mechanisms of poor osseointegration following dental implants in type 2 diabetics, it is important to study the biological properties of alveolar bone osteoblasts isolated from these patients. We collected alveolar bone chips under aseptic conditions and cultured them in vitro using the tissue explants adherent method. The biological properties of these cells were characterized using the following methods: alkaline phosphatase (ALP) chemical staining for cell viability, Alizarin red staining for osteogenic characteristics, MTT test for cell proliferation, enzyme dynamics for ALP contents, radio-immunoassay for bone gla protein (BGP) concentration, and ELISA for the concentration of type I collagen (COL-I) in the supernatant. Furthermore, we detected the adhesion ability of two types of cells from titanium slices using non-specific immunofluorescence staining and cell count. The two cell forms showed no significant difference in morphology under the same culture conditions. However, the alveolar bone osteoblasts received from type 2 diabetic patients had slower growth, lower cell activity and calcium nodule formation than the normal ones. The concentration of ALP, BGP and COL-I was lower in the supernatant of alveolar bone osteoblasts received from type 2 diabetic patients than in that received from normal subjects (P < 0.05). The alveolar bone osteoblasts obtained from type 2 diabetic patients can be successfully cultured in vitro with the same morphology and biological characteristics as those from normal patients, but with slower growth and lower concentration of specific secretion and lower combining ability with titanium than normal ones.

Cryopreservation of cynomolgus monkey (Macaca fascicularis) spermatozoa in a chemically defined extender / 亚洲男科学杂志(英文版)

<p><b>AIM</b>To establish a method for cynomolgus monkey sperm cryopreservation in a chemically defined extender.</p><p><b>METHODS</b>Semen samples were collected by electro-ejaculation from four sexually mature male cynomolgus monkeys. The spermatozoa were frozen in straws by liquid nitrogen vapor using egg-yolk-free Tes-Tris mTTE synthetic extender and glycerol as cryoprotectant. The effects of glycerol concentration (1 %, 3 %, 5 %, 10 % and 15 % [v/v]) and its equilibration time (10 min, 30 min, 60 min and 90 min) on post-thaw spermatozoa were examined by sperm motility and sperm head membrane integrity.</p><p><b>RESULTS</b>The post-thaw motility and head membrane integrity of spermatozoa were significantly higher (P0.05) for 5 % glycerol (42.95 +/- 2.55 and 50.39+/- 2.42, respectively) than those of the other groups (1%: 19.19 +/- 3.22 and 24.84 +/- 3.64; 3%: 34.23 +/- 3.43 and 41.37 +/- 3.42; 10%:15.68 +/- 2.36 and 21.39 +/- 3.14; 15%: 7.47 +/- 1.44 and 12.90 +/- 2.18). The parameters for 30 min equilibration(42.95 +/- 2.55 and 50.39 +/- 2.42) were better (P0.05) than those of the other groups (10 min: 31.33 +/- 3.06 and 38.98 +/- 3.31; 60 min: 32.49 +/- 3.86 and 40.01 +/- 4.18; 90 min: 31.16 +/- 3.66 and 38.30 +/- 3.78). Five percent glycerol and 30 min equilibration yielded the highest post-thaw sperm motility and head membrane integrity.</p><p><b>CONCLUSION</b>Cynomolgus monkey spermatozoa can be successfully cryopreserved in a chemically defined extender, which is related to the concentration and the equilibration time of glycerol.</p>