Background/aims To compare the effects of repeated low-level red light (RLRL) treatment on axial length growth and refractive error changes in myopic and premyopic children. Methods Subjects were assigned randomly to four subgroups: myopia-RLRL group (M-RL), myopia-control group (M-C), premyopia-RLRL group (PM-RL) and premyopia-control group (PM-C). Subjects in the RLRL group completed a 12-month treatment composed of a 3 min RLRL treatment session twice daily, with an interval of at least 4 hours, for 7 days per week. Visits were scheduled before and at 1-month, 3-month, 6-month, 9-month and 12-month follow-up after the treatment. Repeated-measures analysis of variance was used to compare the spherical equivalent refractive errors (SE) and axial length (AL) changes between the groups across the treatment period. Results After 12 months of treatment, in the myopia group, SE and AL changes were −0.078±0.375 D and 0.033±0.123 mm for M-RL and −0.861±0.556 D and 0.415±0.171 mm for M-C; in the premyopia group, the progression of SE and AL was −0.181±0.417 D and 0.145±0.175 mm for PM-RL and −0.521±0.436 D and 0.292±0.128 mm for PM-C. PM-RL indicated a lower myopia incidence than PM-C (2.5% vs 19.4%). Additionally, the percentage of AL shortening in the M-RL was higher than that in the PM-RL before the 9-month follow-up. Conclusion RLRL effectively delayed myopia progression in children with myopia and reduced the incidence of myopia in premyopic children. Moreover, RLRL exhibited a stronger impact on myopic children compared with premyopic individuals.

Boehmite morphology depended on the pH and ions of the solution by hydrothermal treatment of gibbsite owing to the difference in nucleation and growth of boehmite from Al³⁺, Al(OH)₄⁻ or the Al(OH)₄⁻Na⁺ ion pair.

A fine activated alumina with high specific surface area was prepared by phase evolution from sodium aluminate solution, Al(OH)₃ and NH₄Al(OH)₂CO₃. The maximum adsorption capacity was 261.66 mg g⁻¹ and the regenerated material exhibited high performance phosphate removal.