Mechanisms of Polymer-Templated Nanoparticle Synthesis: Contrasting ZnS and Au.

We combine solution small-angle X-ray scattering (SAXS) and high-resolution analytical transmission electron microscopy (ATEM) to gain a full mechanistic understanding of substructure formation in nanoparticles templated by block copolymer reverse micelles, specifically poly(styrene)-block-poly(2-vinylpyridine). We report a novel substructure for micelle-templated ZnS nanoparticles, in which small crystallites (∼4 nm) exist within a larger (∼20 nm) amorphous organic-inorganic hybrid matrix. The formation of this complex structure is explained via SAXS measurements that characterize in situ for the first time the intermediate state of the metal-loaded micelle core: Zn(2+) ions are distributed throughout the micelle core, which solidifies as a unit on sulfidation. The nanoparticle size is thus determined by the radius of the metal-loaded core, rather than the quantity of available metal ions. This mechanism leads to particle size counterintuitively decreasing with increasing metal content, based on the modified interactions of the metal-complexed monomers in direct contrast to gold nanoparticles templated by the same polymer.

Improving Body Mass Index of School-Aged Children Using a Nine-Week Rope Skipping Training Intervention: A One-Group Pre-Test Post-Test Design.

Studies examining the effectiveness of rope skipping training to improve the body mass index (BMI) of school children are scarce. Hence, this study examined the effectiveness of nine-week skipping training on the BMI of primary six school-aged children (n = 77). The participants underwent 30 min of skipping training three days per week over a nine-week period. The participants' BMI was measured at the baseline and during weeks 3, 6 and 9. The results from a one-way ANOVA with repeated measures indicated a statistically significant difference in the BMI for both males [F(3,111) = 9.42, p < 0.001, ηp2 = 0.203] and females [F(3,114) = 7.35, p < 0.001, ηp2 = 0.162], suggesting an improvement in BMI. Post hoc comparisons with a Bonferroni adjustment revealed significant differences in BMI after nine weeks of intervention for males between the pre-test (M = 21.47, SD = 4.94) and the 9-week post-test (M = 20.15, SD = 4.36), and for females between the pre-test (M = 21.56, SD = 5.80) and the 9-week post-test (M = 20.68, SD = 5.32). This study demonstrated that regular participation in vigorous physical activity such as skipping training could promote child health by preventing the likelihood of young children being overweight. This result has implications for the inclusion of skipping training into the school life of school-aged children to help manage their BMI levels.