Effects of Composition Variations on the Crystalline Phases and Photoluminescence Properties of Ca2+x MgSi2Eu0.025O7+x Phosphors.

A solid-state reaction method was used to synthesize Ca2+x MgSi2Eu0.025O7+x (x = 0-1.0) powders in the air atmosphere and in a reduction atmosphere (95% N2 + 5% H2) at 1350 °C and 4 h, and the reduction atmosphere was removed at 800 °C. Only the Ca2MgSi2O7 phase was found in the XRD pattern of the synthesized Ca2MgSi2Eu0.025O7 powder. The first important discovery was that when the x value of Ca2+x MgSi2Eu0.025O7+x powders was increased from 0.2 to 0.8, both Ca2MgSi2O7 and Ca3MgSi2O8 phases coexisted in the synthesized Ca2+x MgSi2Eu0.025O7+x powders, and the diffraction intensity of the Ca2MgSi2O7 (Ca3MgSi2O8) phase decreased (increased) with the x value. The second important discovery was that the Ca2MgSi2Eu0.025O7 phosphor exhibited stronger photoluminescence excitation (PLE), photoluminescence (PL), and decay curve properties than the Ca2.2MgSi2Eu0.025O7.2 phosphor, and the Ca3MgSi2Eu0.025O8 phosphor exhibited stronger PLE, PL, and decay curve properties than the Ca2+x MgSi2Eu0.025O7+x phosphors for x = 0.4, 0.6, and 0.8. For x = 0.2-0.8, the PL spectra of the Ca2+x MgSi2Eu0.025O7+x phosphors were a combination of the PL spectra of Ca2MgSi2Eu0.025O7 and Ca3MgSi2Eu0.025O8 phosphors. The third important discovery was that as the x value was increased, the maximum emission peak wavelengths of the Ca2+x MgSi2Eu0.025O7+x phosphors shifted to a lower value, the maximum emission intensity of the PL spectra increased, and the emission light changed from green and cyan to blue.

Effects of Acute Aerobic Exercise on Executive Function in Children With and Without Learning Disability: A Randomized Controlled Trial.

This study examined the effects of acute aerobic exercise on sustained attention and discriminatory ability of children with and without learning disabilities (LD). Fifty-one children with LD and 49 typically developing children were randomly assigned to exercise or control groups. The participants in the exercise groups performed a 30-min session of moderate-intensity aerobic exercise, whereas the control groups watched a running/exercise-related video. Neuropsychological tasks, the Daueraufmerksamkeit sustained attention test, and the determination tests were assessed before and after each treatment. Exercise significantly benefited performance in sustained attention and discriminatory ability, particularly in higher accuracy rate and shorter reaction time. In addition, the LD exercise group demonstrated greater improvement than the typically developing exercise group. The findings suggest that the acute aerobic exercise influenced the sustained attention and the discriminatory function in children with LD by enhancing regulation of mental states and allocation of attentional resources.

Use of a Sampling Area-Adjusted Adenosine Triphosphate Bioluminescence Assay Based on Digital Image Quantification to Assess the Cleanliness of Hospital Surfaces.

Contaminated surfaces play an important role in the transmission of pathogens. We sought to establish a criterion that could indicate "cleanliness" using a sampling area-adjusted adenosine triphosphate (ATP) assay. In the first phase of the study, target surfaces were selected for swab sampling before and after daily cleaning; then, an aerobic colony count (ACC) plate assay of bacteria and antibiotic-resistant bacteria was conducted. ATP swabs were also tested, and the ATP readings were reported as relative light units (RLUs). The results of the ACC and ATP assays were adjusted according to the sampling area. During the second phase of the study, a new cleaning process employing sodium dichloroisocyanurate (NaDCC) was implemented for comparison. Using the criterion of 2.5 colony-forming units (CFU)/cm², 45% of the sampled sites were successfully cleaned during phase one of the study. During phase two, the pass rates of the surface samples (64%) were significantly improved, except under stringent (5 RLU/cm²) and lax (500 RLU) ATP criteria. Using receiver-operating characteristic curve analysis, the best cut-off point for an area-adjusted ATP level was 7.34 RLU/cm², which corresponded to culture-assay levels of <2.5 CFU/cm². An area adjustment of the ATP assay improved the degree of correlation with the ACC-assay results from weak to moderate.