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Background and Aims The efficacy of a direct application of plasma needle to in vivo wound healing was experimentally studied in mice. This kind of plasma has achieved considerable success in blood coagulation and tissue restoration in mice. In the development of the present study, an argon plasma needle was chosen for coagulation purposes, whereas for healing purposes, a helium plasma needle was used. Methods Treatment was applied with a plasma needle produced by argon and helium to a wound induced in laboratory mice. Tissue regeneration was carried out by three argon plasma treatments with 0.5 SLPM flow for 1 min and three treatments of helium with 1.5 SLPM flow. Intervals between each treatment were 5 min and 60 min for argon and helium plasmas, respectively, thus completing a total treatment time of 180 min. Histological sections were performed to corroborate the internal bleeding and tissue regeneration. Results After three treatments with argon plasma, the blood produced in the wound was coagulated and protein material appeared. By means of treatment with helium plasma, an approach of the wound edges was produced until the conclusion thereof. These results were corroborated histologically. Conclusions This type of acceleration during the skin wound healing process can be attributed to the formation of reactive species such as NO, which were increased in the helium plasma needle with respect to the argon plasma needle.

A new RF power supply intended for low-power plasma torches is presented. It is based on a class-E amplifier, modified on the principle of a parallel LC resonant circuit, and is used here to supply the so-called 'plasma needle'. The latter is matched with a shunt inductor, and both are connected in parallel to the resonant capacitor C. This configuration is particularly useful for the control of stable discharge characteristics, for example, to resist naturally occurring variations in the load impedance, by providing the high voltage necessary to ignite and maintain the plasma. The overall system has been tested at atmospheric pressure by producing glow discharges in flows of helium and argon. We present early results that describe the device's characteristics.

Aluminium is the third more abundant element in the Earth crust. The metal exhibits useful properties such as low density, high strength, good formability and a high resistance to corrosion. Aluminium can gain significant mechanical strength by means of alloying, whereby it is the most used metal after steel. In this sense, aluminium properties depend on its purity and its crystalline structure is face centred cubic [Wang et al, 1999]. Aluminium is, among other characteristics, malleable, easily machined and very ductile. Its high sensitivity to oxidation endows it with a waterproof passivation layer, typically 5-20μm thick according to the prevailing humidity, considerably adherent, which contributes to corrosion tolerance and general durability. The passivation layer consists of the amphoteric aluminium oxide Al2O3, often known as alumina or aloxite in mining and materials science. As corrosion is a major source of failure in Materials Engineering, aluminium is an obvious choice to face aggressive environments, including the atmospheric one. Aluminium as a pure element has a low mechanical resistance which prevents its application under deformation and fracture conditions. Thus, low density combined with good resistance make aluminium alloys very attractive in design considerations. The properties of these alloys depend on a complex interaction among chemical composition, microstructural failures in solidification, thermal treatments, etc. although an increase in the alloy content tends, in general, to diminish the tolerance to corrosion. That is why quenching processes have been developed to improve the response to corrosion of highly alloyed materials. It is essential to select the precise alloy to match the resistance, ductibility, formability, solubility, corrosion tolerance, etc., required by an application. Modifying aluminium composition by the adding nitrogen in an ion implantation process provides the treated samples with surface hardness and improved tribological properties by heating them in a nitrogen rich atmosphere. In this way, at low doses, aluminium nitride (AlN) becomes structured in the shape of clusters, the nitride content clearly increasing with the dose. Ion implantation is applied to pieces subjected to major friction and load forces such as rolling tracks, cylinder sleeves, etc., which require some core plasticity enabling