RESUMEN
The properties of oxide dispersion-strengthened steels are highly dependent on the nature and size distribution of their constituting nano-oxide precipitates. A fine control of the processes of synthesis would enable the optimization of pertinent properties for use in various energy systems. This control, however, requires knowledge of the precise mechanisms of nucleation and growth of the nanoprecipitates, which are still a matter of debate. In the present study, nano-oxide precipitates were produced via the implantation of Y, Ti, and O ions in two different sequential orders in an Fe-10%Cr matrix that was subsequently thermally annealed. The results show that the oxides that precipitate are not necessarily favoured thermodynamically, but rather result from complex kinetics aspects related to the interaction between the implanted elements and induced defects. When Y is implanted first, the formation of nanoprecipitates with characteristics similar to those in conventionally produced ODS steels, especially with a core/shell structure, is evidenced. In contrast, when implantation starts with Ti, the precipitation of yttria during subsequent high-temperature annealing is totally suppressed, and corundum Cr2O3 precipitates instead. Moreover, the systematic involvement of {110} matrix planes in orientation relationships with the precipitates, independently of the precipitate nature, suggests matrix restriction effects on the early stages of precipitation.
RESUMEN
The presence of suicidal manifestations (thoughts and behavior) was studied in a cohort of 30 patients with mild to moderate depression during a 6-week treatment with the serotonin-norepinephrine reuptake inhibitor, milnacipran. At baseline mild suicidal thoughts were present in 46.7% of patients, the mean Hamilton Depression Rating Score (HDRS(17)) was 23.9 +/- 1.8 and the mean suicidality score on the Beck Scale for Suicidal Ideation (BSS) was 4.9 +/- 4.9. Suicidal thoughts decreased progressively throughout the study in parallel with other depressive symptoms. At no time during treatment was there any indication of an increased suicidal risk. Notably, the items retardation and psychic anxiety on the HDRS(17) decreased in parallel. This may possibly explain the lack of any "activation syndrome", which is occasionally observed at the early stages of therapy with some antidepressants and may be linked to a temporary increase in suicidal ideation. To our knowledge this is the first detailed report of suicidality during treatment with milnacipran.
