Quality of life of children and adolescents with chronic kidney disease: a cross-sectional study.

OBJECTIVE: The aim was to compare quality of life (QoL) among children and adolescents with different stages of chronic kidney disease (CKD) and determine factors associated with changes in QoL. DESIGN: Cross-sectional. SETTING: The Kids with CKD study involved five of eight paediatric nephrology units in Australia and New Zealand. PATIENTS: There were 375 children and adolescents (aged 6-18 years) with CKD, on dialysis or transplanted, recruited between 2013 and 2016. MAIN OUTCOME MEASURES: Overall and domain-specific QoL were measured using the Health Utilities Index 3 score, with a scale from -0.36 (worse than dead) to 1 (perfect health). QoL scores were compared between CKD stages using the Mann-Whitney U test. Factors associated with changes in QoL were assessed using multivariable linear and ordinal logistic regression. RESULTS: QoL for those with CKD stages 1-2 (n=106, median 0.88, IQR 0.63-0.96) was higher than those on dialysis (n=43, median 0.67, IQR 0.39-0.91, p<0.001), and similar to those with kidney transplants (n=135, median 0.83, IQR 0.59-0.97, p=0.4) or CKD stages 3-5 (n=91, 0.85, IQR 0.60-0.98). Reductions were most frequent in the domains of cognition (50%), pain (42%) and emotion (40%). The risk factors associated with decrements in overall QoL were being on dialysis (decrement of 0.13, 95% CI 0.02 to 0.25, p=0.02), lower family income (decrement of 0.10, 95% CI 0.03 to 0.15, p=0.002) and short stature (decrement of 0.09, 95% CI 0.01 to 0.16, p=0.02). CONCLUSIONS: The overall QoL and domains such as pain and emotion are substantially worse in children on dialysis compared with earlier stage CKD and those with kidney transplants.

Observation of asymptotic localization of a wave packet.

We present the experimental observation of asymptotic localization, a new regime of wave packet localization under the action of an external linear potential gradient. We employ arrays of evanescently coupled waveguides and directly observe the wave packet trajectory, which exhibits an oscillation with vanishing amplitude and period.

Klein tunneling in deformed honeycomb lattices.

We study the scattering of waves off a potential step in deformed honeycomb lattices. For deformations below a critical value, perfect Klein tunneling is obtained; i.e., a potential step transmits waves at normal incidence with nonresonant unit-transmission probability. Beyond the critical deformation a gap forms in the spectrum, and a potential step perpendicular to the deformation direction reflects all normally incident waves, exhibiting a dramatic transition form unit transmission to total reflection. These phenomena are generic to honeycomb lattices and apply to electromagnetic waves in photonic lattices, quasiparticles in graphene, and cold atoms in optical lattices.

Symmetry breaking in honeycomb photonic lattices.

We study the phenomena associated with symmetry breaking in honeycomb photonic lattices. As the honeycomb structure is gradually deformed, conical diffraction around its diabolic points becomes elliptic and eventually no longer occurs. As the deformation is further increased, a gap opens between the first two bands, and the lattice can support a gap soliton. The existence of the gap soliton serves as a means to detect the symmetry breaking and provide an estimate of the size of the gap.