44 research outputs found
Laser-Induced Crystallization of Sputtered Unhydrogenated Silicon at Low Temperatures
10-um-thick non-hydrogenated amorphous-silicon (a-Si) films were deposited at relatively high rates (_>10 Å/s) by radio-frequency magnetron sputtering (RFMS) on different large-area buffer-layer-coated glass substrates at deposition temperatures ranging from room temperature (RT) to 300oC. These amorphous samples were subsequently crystallized by means of a continuous-wave diode laser, looking for conditions to reach liquid-phase crystallization. The influence of deposition conditions on the quality of the final micro-crystalline silicon films has been studied
Domain Wall Propagation and Pinning Induced by Current Pulses in Cylindrical Modulated Nanowires
The future developments of three-dimensional magnetic nanotechnology require
the control of domain wall dynamics by means of current pulses. While this has
been extensively studied in planar magnetic strips (planar nanowires), few
reports exist in cylindrical geometry, where Bloch point domain walls are
expected to have intriguing properties. Here we report this investigation in
cylindrical magnetic Ni nanowires with geometrical notches. Experimental work
based on synchrotron X-ray magnetic circular dichroism (XMCD) combined with
photoemission electron microscopy (PEEM) indicates that large current densities
induce domain wall nucleation while smaller currents move domain walls
preferably against the current direction. In the region where no pinning
centers are present we found domain wall velocity of about 1 km/s. The domain
wall motion along current was also detected in the vicinity of the notch
region. Pinning of domain walls has been observed not only at geometrical
constrictions but also outside of them. Thermal modelling indicates that large
current densities temporarily raise the temperature in the nanowire above the
Curie temperature leading to nucleation of domain walls during the system
cooling. Micromagnetic modelling with spin-torque effect shows that for
intermediate current densities Bloch point domain walls with chirality parallel
to the Oersted field propagate antiparallel to the current direction. In other
cases, domain walls can be bounced from the notches and/or get pinned outside
their positions. We thus find that current is not only responsible for the
domain wall propagation but is also a source of pinning due to the Oersted
field action
In Vitro and In Vivo Efficacy of Ether Lipid Edelfosine against Leishmania spp. and SbV-Resistant Parasites
Leishmaniasis represents a major international health problem, has a high morbidity and mortality rate, and is classified as an emerging and uncontrolled disease by the World Health Organization. The migration of population from endemic to nonendemic areas, and tourist activities in endemic regions are spreading the disease to new areas. Unfortunately, treatment of leishmaniasis is far from satisfactory, with only a few drugs available that show significant side-effects. Here, we show in vitro and in vivo evidence for the antileishmanial activity of the ether phospholipid edelfosine, being effective against a wide number of Leishmania spp. causing cutaneous, mucocutaneous and visceral leishmaniasis. Our experimental mouse and hamster models demonstrated not only a significant antileishmanial activity of edelfosine oral administration against different wild-type Leishmania spp., but also against parasites resistant to pentavalent antimonials, which constitute the first line of treatment worldwide. In addition, edelfosine exerted a higher antileishmanial activity and a lower proneness to generate drug resistance than miltefosine, the first drug against leishmaniasis that can be administered orally. These data, together with our previous findings, showing an anti-inflammatory action and a very low toxicity profile, suggest that edelfosine is a promising orally administered drug for leishmaniasis, thus warranting clinical evaluation