4 research outputs found
Research on Influences of Transient High IOP during LASIK on Retinal Functions and Ultrastructure
Objectives. To study the influences of transient high intraocular pressure(IOP) during LASIK on retinal functions and ultrastructure. Methods. Thirty-two New Zealand white rabbits were randomly divided into normal control, experimental control, negative suction 20 s and negative suction 3 min groups. The experimental control group was treated only by laser. Rabbit eyes received suction for different periods of time (20 s, 3 min) by negative pressure generator in different groups. The changes of neuro-optic and retinal ultrastructure were observed under electron and light microscopes; retinal neurofunctional changes were observed with flash-visual evoked potential (F-VEP) and flash-electroreinogram (F-ERG). Results. There was no obvious change in optic nerve, retina, ERG a-wave and b-wave in normal control and experimental control groups. There were slight changes in tissues of optic nerve and retina at various times of suction 20 s compared with control group, and a sharp change in suction 3 min group within 14d after operation, but these changes recovered at 28d . Amplitude of ERG b-wave observed at different time will decrease with suction periods prolonged. It can recover to normal level with the prolonged recovery periods. Amplitude and incubation period of ERG a-wave and VEP-P did not change significantly after different duration of suction. Conclusions. The transient high IOP during LASIK might have influence on retinal function and ultrastructure, but these changes were reversible
Thermally enhanced photoluminescence and temperature sensing properties of ScWO:Eu phosphors
Currently,lanthanide ions doped luminescence materials applying as optical
thermometers have arose much concern. Basing on the different responses of two
emissions to temperature, the fluorescence intensity ratio (FIR) technique can
be executed and further estimate the sensitivities to assess the optical
thermometry performances. In this study, we introduce different doping
concentrations of Eu ions into negative expansion material
ScWO:Eu, accessing to the thermal enhanced luminescence
from 373 to 548 K, and investigate the temperature sensing properties in
detail. All samples exhibit good thermally enhanced luminescence behavior. The
emission intensity of ScWO: 6 mol% Eu phosphors reaches
at 147.81% of initial intensity at 473 K. As the Eu doping concentration
increases, the resistance of the samples to thermal quenching decreases. The
FIR technique based on the transitions 5D0-7F1 (592 nm) and 5D0-7F2 (613 nm) of
Eu ions demonstrate a maximum relative temperature sensitivity of 3.063%
K-1 at 298 K for ScWO:Eu: 6 mol% Eu phosphors. The
sensitivity of sample decreases with the increase of Eu concentration.
Benefiting from the thermal enhanced luminescence performance and good
temperature sensing properties, the ScWO:Eu: Eu
phosphors can be applies as optical thermometers