Stabilization of Magnetic Skyrmions on Arrays of Self-Assembled Hexagonal Nanodomes for Magnetic Recording Applications.

Magnetic skyrmions are nontrivial spin textures that resist external perturbations, being promising candidates for the next-generation recording devices. Nevertheless, a major challenge in realizing skyrmion-based devices is the stabilization of ordered arrays of these spin textures under ambient conditions and zero applied field. Here, we demonstrate for the first time the formation and stabilization of magnetic skyrmions on the arrays of self-assembled hexagonal nanodomes taking advantage of the intrinsic properties of its curved geometry. Magnetic force microscopy images from the arrays of 100 nm nanodomes showed stable skyrmions at the zero field that are arranged following the topography of the nanostructure. Micromagnetic simulations are compared to the experiments to determine the correlation of the domain textures with the topography of the samples. We propose a simple method to nucleate and annihilate skyrmions, opening the possibility for an ultradense data storage based on the high stability and low energy consumption of the skyrmionic textures.

Effects of weekly LED therapy at 625 nm on the treatment of chronic lower ulcers.

The aim of this study was to evaluate the effects of LED therapy associated with compression therapy on chronic venous leg ulcers (CVUs). The study included CVU patients (n = 17, eight men) who were eligible for Unna's boot treatment. Ulcers were treated on a weekly basis with either LED therapy (625 nm, 4 J/cm(2)) and an Unna's boot (LED ulcers, n = 14) or a placebo treatment and an Unna's boot (control ulcers, n = 14). The total surface area of the ulcers, the relative ulcer area, and the healing rate were recorded over a period of 30 weeks. Ulcer exudates were collected for determination of local tumor necrosis factor alpha (TNF-α) levels. The total area was not significantly different between the LED and control ulcers (P > 0.05, Mann-Whitney U test) throughout the study. However, the relative area indicated that non-healing treatment resistant ulcers (n = 6) persisted in the control group after 19 weeks (P < 0.05, Mann-Whitney U Test). No differences in median healing rate were observed (hazard ratio 0.89, CI 95%: 0.40-1.98) between LED (15 weeks) and control ulcers (19.5 weeks). No differences in TNF-α levels were detected (P > 0.05, Mann-Whitney U test). The results suggest that LED therapy improved the effectiveness of the Unna's boot since no refractory ulcer was observed in the LED group after 19 weeks. However, LED therapy did not alter the local secretion of TNF-α nor accelerate wound healing.

Features of host cell invasion by different infective forms of Trypanosoma cruzi

Through its life cycle from the insect vector to mammalian hosts Trypanosoma cruzi has developed clever strategies to reach the intracellular milieu where it grows sheltered from the hosts' immune system. We have been interested in several aspects of in vitro interactions of different infective forms of the parasite with cultured mammalian cells. We have observed that not only the classically infective trypomastigotes but also amastigotes, originated from the extracellular differentiation of trypomastigotes, can infect cultured cells. Interestingly, the process of invasion of different parasite infective forms is remarkably distinct and also highly dependent on the host cell type.