No abstract

Cytomegalovirus colitis in immunocompetent patients has rarely been reported without another severe illness. The prognosis is usually bad, leading to toxic megacolon or death due to multi-organ system failure. We report a case of a self-limited cytomegalovirus colitis in a young patient with no risk factor for CMV infection or associated disease. This suggests that self-limiting CMV colitis may be more frequent than is usually believed, and its prognosis may be better in young patients with normal immune functions. Therefore it should be sought systematically even in immunocompetent young patients.

Light induced grating experiments have been performed at room temperature in CdS nanocrystallites of 2.5 nm radius embedded in sol-gel glass films of different semiconductor volume concentration. The dynamics of the photogenerated carriers at the lowest transition peak has been shown to depend on the excitation intensity. No spatial diffusion is observed up to a nanocrystallite volume concentration of 35%. Below a few MW/cm2 the carriers relax in each nanocrystallite, either radiatively in ∼150 ps or by trapping the electrons 15 meV below their excitation transition. For higher intensities of excitation, a saturation of the excited states occurs which allows the electrons to be trapped in the glass matrix, inducing a permanent grating by the creation of a static electric field.

No abstract

No abstract