RESUMO
We report on a high resolution x-ray diffraction study unveiling the effect of carriers optically injected into (In,Ga)As quantum dots on the surrounding GaAs crystal matrix. We find a tetragonal lattice expansion with enhanced elongation along the [001] crystal axis that is superimposed on an isotropic lattice extension. The isotropic contribution arises from excitation induced lattice heating as confirmed by temperature dependent reference studies. The tetragonal expansion on the femtometer scale is tentatively attributed to polaron formation by carriers trapped in the quantum dots.
RESUMO
Trichograms from the parietal and occipital area were evaluated in 34 patients with thyroid diseases, which complained about hair loss. The followings findings can be regarded as characteristic for alopecia in thyroid diseases, being not related to the functional state of the thyroid gland: increase of dysplastic hairs over 50%, increase of broken hairs over 15% and strenghthening of these findings in the occipital area. Alopecia in thyroid diseases is not caused by changes within the hair cycle but probably by impaired hair quality.