RESUMO
The studies cited in this paper demonstrate that the unique environment provided by L. B. films and supported multilayers can produce a variety of molecular effects on photochemical reactivity that can, in turn, result in films, interfaces or surfaces having macroscopic properties which can be modulated by light. Although these investigations have been focused on molecular reactivity in films and how it can be modified (or persist unchanged), the results suggest several possible technological applications which might result from investigations directed more closely to them.
Assuntos
Alcenos/efeitos da radiação , Corantes/efeitos da radiação , Membranas Artificiais , Fluorescência , Isomerismo , Fotoquímica , Radiossensibilizantes , Relação Estrutura-Atividade , TensoativosRESUMO
BACKGROUND: Individuals with subjective cognitive impairment (SCI) have persistent memory complaints but normal neurocognitive performance. For some, this may represent a pre-mild cognitive impairment (MCI) stage of Alzheimer's disease (AD). Given that attentional deficits and associated brain activation changes are present early in the course of AD, we aimed to determine whether SCI is associated with brain activation changes during attentional processing. METHODS: Eleven SCI subjects and 10 controls completed a divided attention task during functional magnetic resonance imaging. RESULTS: SCI and control groups did not differ in sociodemographic, neurocognitive or behavioural measures. When group activation during the divided attention task was compared, the SCI group demonstrated increased activation in left medial temporal lobe, bilateral thalamus, posterior cingulate and caudate. CONCLUSION: This pattern of increased activation is similar to the pattern of decreased activation reported during divided attention in AD and may indicate compensatory changes. These findings suggest the presence of early functional changes in SCI; longitudinal studies will help to further elucidate the relationship between SCI and AD.
Assuntos
Doença de Alzheimer , Atenção/fisiologia , Mapeamento Encefálico/métodos , Análise e Desempenho de Tarefas , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/patologia , Doença de Alzheimer/fisiopatologia , Doença de Alzheimer/psicologia , Encéfalo/patologia , Encéfalo/fisiopatologia , Diagnóstico Precoce , Feminino , Humanos , Testes de Inteligência , Imageamento por Ressonância Magnética , Masculino , Rememoração Mental/fisiologia , Pessoa de Meia-Idade , Testes Neuropsicológicos , Tempo de Reação/fisiologia , Índice de Gravidade de Doença , Perfil de Impacto da DoençaRESUMO
People with Subjective Cognitive Impairment (SCI) may be at increased risk of dementia. In this study we examined amyloid load in 5 SCI subjects and 14 controls using PIB PET scanning. One SCI subject had significantly increased PIB retention in the cortical areas of interest. Larger, longitudinal studies are indicated.