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Objective: an innovative non-thermal plasma (NTP) system constituted by a radiofrequency (RF) power generator directly coupled to a treatment probe is described and characterized. This system is intended to be applied as a medical device for therapeutic treatments., Methods: electrical characterization of the radiofrequency power generator supplying the treatment probe was performed. Meanwhile, generated NTP was optically analyzed. Obtained data were studied to establish the safety profile of plasma application on heat sensitive matter., Results: the NTP system was validated through bacterial deactivation trials, as well as, of being capable of deactivating carcinogenic cells. Besides promoting and accelerating wound closure in vivo performed in mice, demonstrating faster healing than that done with conventional treatments., Conclusion: the NTP system's characterization is an essential stage to determine the adequate application of the generated plasma over organic media. The therapeutic benefits of the NTP system were proved by the development of in vivo experiences involving laboratory mice., Significance: the generated NTP interacts with surrounding air particles producing reactive oxygen and nitrogen species, which, exhibit bactericidal and antiseptic effects due to their strong biochemical reactivity; functioning like critical mediators in animal physiology and promoting wound healing processes. These properties make the NTP system a feasible technology intended for therapeutic treatments.

The aim of the present study is to determine the deoxyribonucleic acid (DNA) damage by cells exposed to atmospheric pressure non-thermal plasma (APNTP). Mouse leukocytes embedded in agarose were exposed to the plasma at two different distances from a helium plasma needle outlet and during three different exposure periods. Damage was assessed by the single cell gel electrophoresis assay. The results indicate that, at 0.1 cm from the plasma needle, the exposure caused complete DNA fragmentation determined by the presence of so called "clouds". Samples exposed at 0.5 cm from the slide sample surface presented damage proportional to the exposure periods in terms of tail intensity, tail moment and "clouds" frequency. Studies performed with alkaline single cell gel electrophoresis assay to determine DNA breaks and alkali-labile sites, indicates that DNA damage produced by exposure to APNTP was caused mainly by oxidative radicals, rather than by UV light which causes cyclobutane pyrimidine dimers. These results allow us to conclude that plasma needle induced DNA breaks in mice leukocytes proportionally to exposure time.

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., (Copyright © 2013 IMSS. Published by Elsevier Inc. All rights reserved.)

The aim of this work is the study of the carbonaceous and metal soot deposits in a low voltage circuit breaker. The deposits on the walls of the circuit breaker were analyzed by Raman Spectroscopy, X-Rays Diffraction (XRD) and Scanning Electron Microscopy (SEM), These experimental results were confronted with the theoretical predictions of a computer code of multiphasic equilibrium composition of the arc plasma in extinction. [ABSTRACT FROM AUTHOR]

Abstract: Films of titanium dioxide (TiO2) in the rutile and anatase phases have been obtained in a cylindrical pyrex-like glass vessel inductively coupled to a 13.56MHz radio frequency generator. Rutile films were developed from commercially pure (CpTi) titanium samples used as targets in an argon/oxygen plasma. Each CpTi target was biased at −3000V by means of a direct current supply. The plasma ion acceleration at such a potential leads to a kinetic energy transference to the target whose temperature rises to ∼670°C, favourable to the rutile formation. The anatase films were obtained from sputtering the titanium targets over glass and silicon electrically floated substrates. The latter were placed 3cm away from the target. The substrates attained a temperature resulting from the amount of heat transferred by the plasma particles, in turn, a function of the plasma parameters. Thus, under the prevailing experimental conditions, substrate temperatures lay in the ∼280 to 325°C range. Atomic titanium is assumed to be sputtered out of the target and oxidised, evolving into the anatase phase on the surface of the glass or silicon. The obtained film phases did not require annealing after the plasma oxidation process. The characterisation of the film samples was conducted by means of X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscopy (SEM). [Copyright &y& Elsevier]

Abstract: Monitoring basic plasma parameters such as temperature (T), density (n), floating potential (Vf) or Debye length (λd) provides vital knowledge during the ion implantation processing of materials immersed in plasmas (PIII or PSII) generated either by DC or (13.56MHz) RF sources. Thus, a fully automated electromechanical system has been designed and constructed on the basis of guard double electric probes in order to prevent both probe erosion and plasma contamination. The electronic components of the system comprise a ±150V triangular and ramp wave form generator capable of supplying ±50μA to ±100mA currents at 1–2000Hz frequencies and a DAQ PCI-6023E data acquisition board with a 12 bit resolution compatible with LabVIEW graphic language. A program has been specifically developed for the latter in order to control the probe position within the discharge vessel and to capture, filter, visualize, process and store the respective information. The system has been experimentally applied to DC and RF plasmas of helium, argon, nitrogen, oxygen, and multiple gas mixtures with great success, inside several PIII reactors. Results are presented free from RF interference from the process itself or other surrounding sources. [Copyright &y& Elsevier]