Spintronics is a new branch of electronics based on purely quantum effects. Instead of carrier charge transfer, as in usual electronics, it evokes carrier's spin transfer. The search of new materials ...suitable for injecting and transferring carriers with a preferential spin orientation is of paramount importance for the development of spintronics. Here we report a first experimental evidence of room temperature direct spin polarized injection in sexithienyl (T
6), a prototypical organic semiconductor, from colossal magnetoresistance manganite La
0.7Sr
0.3MnO
3 (LSMO). A strong magnetoresistance (up to 30%) was measured on nanostructured planar hybrid junctions LSMO/T
6/LSMO. The spin diffusion length in T
6 is about 200
nm at room temperature. The results are discussed taking into account possible spin-flip mechanisms in organic material and interface effects.
Wound cleansing represents a fundamental step in chronic wound management. Several investigations in recent years have led to a refinement of the wound cleansing protocol in order to obtain a better ...control of the bacterial burden during wound bed preparation and to avoid further cell and tissue damage. The aim of the present randomized controlled trial was to investigate the effects of a wound cleansing solution containing polihexanide and betaine in venous leg ulcers by means of clinical and instrumental assessment. A portable device was used on the wound bed to assess surface pH, which has been shown to be one of the most useful non-invasive biophysical parameters in order to correlate the level of bacterial burden in different types of chronic wounds. Baseline pH on the wound surface (median range) was initially 8.9, and after 4 weeks of cleansing treatment and moist wound dressing was reduced and stable at 7.0 in the group treated with active cleanser. The pH value was significantly lower (p < 0.05) in this group compared to the control group at the end of the study. The treatment with the solution containing polihexanide and betaine was well tolerated by the patients and was found useful in the absorption of wound odours.
The effect of laser irradiation on the structure and properties of the YBa
2
Cu
3
O
7 − δ
epitaxial super-conducting films (
T
c
= 90–91 K) that are grown on the SrTiO
3
and LaAlO
3
substrates is ...studied. The films exhibit a system of pyramidal peaks that are incorporated in the single-crystal structure of the film whose system of the (00
l
) planes is parallel to the surface of the substrate. It is demonstrated that the peaks represent growth defects that result from the relaxation of the accumulating strain due to the mismatch of the crystallographic parameters of the growing layers of the film and substrate. The island structures that are formed owing to the relaxation of strains acquire the (11
l
) or (10
l
) orientation and penetrate through the film layers in the course of growth. It is demonstrated that the irradiation using relatively short laser pulses makes it possible to modify the structure of the dielectric clusters and allows the smoothing of the film surface at an insignificant (5–10%) decrease in the concentration of the superconducting phase. An increase in the energy density to a level of greater than 100 mJ/cm
2
when the number of pulses is greater than five causes an increase in the volume of dielectric phases and the worsening of parameters.
Measurements of the critical current density dependence on the direction of the external magnetic field vector H have been performed on Nb/CuMn multilayers with and without a regular square lattice ...of submicrometre antidots. (i) At small angles between H and the surface of the sample, the presence of the antidot array strongly influences the topology of the flux lines. In the multilayers without the antidot array the vortex topology is mainly due to the anisotropy of the system with the formation of kinked vortices in the samples with higher values of the anisotropy parameter. In antidotted samples, the presence of kinked vortices is not related to the anisotropy of the system but to the geometry of the antidot array. (ii) At large angles between H and the surface of the sample, the dimensions of the antidots determine the pinning mechanism, with the prevalence of edge pinning when the antidot diameter is larger than the magnetic penetration depth lambda and the presence of electromagnetic pinning when the diameter is comparable to lambda. A phenomenological expression for the angular dependence of the pinning force at intermediate and large angles is proposed, satisfactorily describing the experimental data.
Epitaxial YBCO superconducting thin films have been grown in-situ by XeCl excimer laser ablation using an off-axis deposition geometry. This PLD geometry allows to obtain films with an excellent ...surface morphology without droplets or other particulates. The as-obtained YBCO films exhibit good structural and superconducting properties with
T
c(
R = 0)
=89.5 K,
R
(300)/
R
(100)=2.8,
ΔT = 1.3 K,
J
c = 2 × 10
6 A/cm
2 (at 77 K and zero magnetic field) and full width half maximum of the rocking curve of the (005) YBCO peak of about 0.16°. These structural and electrical properties are very close to those of the YBCO films deposited by the conventional PLD on-axis geometry.
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