RESUMO
Memory structures with an embedded sheet of separated Si nanocrystals were prepared by low pressure chemical vapour deposition using a Si3N4 control layer and different Si2O2 or Si3N4 tunnel layers. It was obtained that Si nanocrystals improve the charging behaviour of the MNOS structures. Memory window width of 1.3 V and 2.0 V were obtained for pulse amplitudes of +/-9 V and +/-10 V, 100 ms, respectively. The extrapolated memory window after 10 years is about 15% of its initial value.
RESUMO
Ge nanocrystals were formed by electron beam evaporation on SiO2 covered Si substrates. The size and distribution of the nanocrystals were studied by atomic force microscopy, scanning electron microscopy and cross-sectional transmission electron microscopy. Dependencies of the nanocrystal size, of the nanocrystal surface coverage, and sheet resistance obtained by van der Pauw method of the Ge layer have been found on the evaporation time. The suggested growth mechanism for the formation of nanocrystals is the Volmer-Weber type. The sheet resistance exhibited a power dependence on the nanocrystal size.
RESUMO
Potential risk factors responsible for development of doxorubicin-induced congestive heart failure were examined through retrospective analysis of 4018 patient records. The overall incidence of drug-induced congestive heart failure was 2.2% (88 cases). The probability of incurring doxorubicin-induced congestive heart failure was related to the total dose of doxorubicin administered. There was a continuum of increasing risk as the cumulative amount of administered drug increased. A weekly dose schedule of doxorubicin was associated with a significantly lower incidence of congestive heart failure than was the usually employed every 3-week schedule. An increase in drug-related congestive heart failure was also seen with advancing patient age. Performance status, sex, race, and tumor type were not risk factors. These data will enable clinicians to better estimate the risk/benefit ratio in individual patients receiving prolonged administration of doxorubicin. They also provide a basis for the investigation of less cardiotoxic anthracycline analogues or for designing measures to prevent doxorubicin-induced cardiomyopathy.