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Background Context Traumatic spinal cord injury (SCI) causes irreversible damage with loss of motor, sensory, and autonomic functions. Currently, there is not an effective treatment to restore the lost neurologic functions. Purpose Injection of polypyrrole-iodine(PPy-I) particle suspension is proposed as a therapeutic strategy. Study Design This is an in vivo animal study. Methods This study evaluates the use of such particles in rats after SCI by examining spared nervous tissue and the Basso, Beattie, and Bresnahan (BBB) scale to evaluate the functional outcome. Diffusive magnetic resonance imaging (MRI) was employed to measure the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) as non-invasive biomarkers of damage after SCI. Results Fractional anisotropy decreased, whereas ADC increased in all groups after the lesion. There were significant differences in FA when compared with the SCI-PPy-I group versus the SCI group (p 2 =0.449, p 2 =0.395, p 2 =0.367, p 2 =0.421, p Conclusions The results suggested that PPy-I is neuroprotective as it decreased the amount of damaged tissue while improving the motor function. Non-invasive MRI proved to be useful in the characterization of SCI and recovery.

Traumatic spinal cord injury (TSCI) can cause paralysis and permanent disability. Rehabilitation (RB) is currently the only accepted treatment, although its beneficial effect is limited. The development of biomaterials has provided therapeutic possibilities for TSCI, where our research group previously showed that the plasma-synthesized polypyrrole/iodine (PPy/I), a biopolymer with different physicochemical characteristics than those of the PPy synthesized by conventional methods, promotes recovery of motor function after TSCI. The present study evaluated if the plasma-synthesized PPy/I applied in combination with RB could increase its beneficial effects and the mechanisms involved. Adult rats with TSCI were divided into no treatment (control); biopolymer (PPy/I); mixed RB by swimming and enriched environment (SW/EE); and combined treatment (PPy/I + SW/EE) groups. Eight weeks after TSCI, the general health of the animals that received any of the treatments was better than the control animals. Functional recovery evaluated by two scales was better and was achieved in less time with the PPy/I + SW/EE combination. All treatments significantly increased βIII-tubulin (nerve plasticity) expression, but only PPy/I increased GAP-43 (nerve regeneration) and MBP (myelination) expression when were analyzed by immunohistochemistry. The expression of GFAP (glial scar) decreased in treated groups when determined by histochemistry, while morphometric analysis showed that tissue was better preserved when PPy/I and PPy/I + SW/EE were administered. The application of PPy/I + SW/EE, promotes the preservation of nervous tissue, and the expression of molecules related to plasticity as βIII-tubulin, reduces the glial scar, improves general health and allows the recovery of motor function after TSCI. The implant of the biomaterial polypyrrole/iodine (PPy/I) synthesized by plasma (an unconventional synthesis method), in combination with a mixed rehabilitation scheme with swimming and enriched environment applied after a traumatic spinal cord injury, promotes expression of GAP-43 and βIII-tubulin (molecules related to plasticity and nerve regeneration) and reduces the expression of GFAP (molecule related to the formation of the glial scar). Both effects together allow the formation of nerve fibers, the reconnection of the spinal cord in the area of injury and the recovery of lost motor function. The figure shows the colocalization (yellow) of βIII-tubilin (red) and GAP-43 (green) in fibers crossing the epicenter of the injury (arrowheads) that reconnect the rostral and caudal ends of the injured spinal cord and allowed recovery of motor function.

Organometallic compounds made of titanium oxide (TiOx) and pyrrole (Py) were synthesized by plasma to combine the photoelectronic activity of TiO and Py in hybrid materials with potential use in photostimulated processes as photoelectronic devices in pollutant degradation or in solar photocollectors. The Ti precursors were based on titanium tetrapropoxide combined with Py in 1:1 mass ratio in a vacuum tubular glass reactor under resistive electrical glow discharges of water vapor plasmas. The TiOx–Py hybrid compounds with x in the 2.75–3.55 interval absorbed electromagnetic radiation in two regions with different intensities. The first and most intense one was from approximately 190 to 350 nm and the other from roughly 350 to 900 nm, which indicates that in the first interval, the TiO fraction dominates the absorption and that the activity of the second region belonged to Py segments. The electrical conductivity was in the (10−6–10−10) S/m interval with activation energy in the (0.015–2.42) eV range, depending on the reaction time and synthesis conditions.

Most of the biomaterials used nowadays for the reconstruction of the spinal cord (SC) tissue after an injury, tested in animals, have obtained modest results. This work presents a study about the compatibility of two novel, non-biodegradable, semi-conductive materials, obtained by plasma polymerization: iodine-doped pyrrole (PPy/I) and pyrrole-polyethylene glycol (PPy/PEG). Both polymers, separately, were implanted in the SC tissue of rats after a transection. Prior to implantation, the elemental composition and the physico-chemical properties of polymers were studied by electron scanning microscopy, IR Spectroscopy and thermogravimetric analysis. We used adult female Long Evans rats, subjected to SC transection. Animals were randomized to be allocated in one of the treatment groups and were killed four weeks after the lesion for histology study. Results showed that both implants were integrated to the SC tissue, as inflammatory and gliotic responses, similar to those observed in the control group, and rejection of the implant, were not evident. Moreover, the immediate effect of PPy/I or PPy/PEG in the injured SC prevented secondary tissue destruction, as compared to non-implanted control animals. In conclusion, implants of semi-conductive polymers were well-tolerated and integrated favorably to SC tissue after transection.

The evaluation of the electron temperature, density, and plasma potential in a glow cleaning discharge hydrogen plasma in the Novillo tokamak is presented. The objective was to investigate the plasma conditions allowing the removal of impurities from the vacuum vessel, thus avoiding the formation of other chemical compounds that could remain adhered to its inner walls. The discharges were accomplished through two anodes and one cathode within the 0.07 to 0.2-mbar-pressure interval at a power density in the range of 100 to 900 W/m{sup 2}. The plasma parameters were obtained using Langmuir probes. The results indicated that the electron temperature lay between 3 and 10 eV, the electron density was approximately 10{sup 8} to 10{sup 9} cm{sup -3}, and the plasma potential was in the 10- to 18-V range. The electron energy was in the range of the dissociation energy for most impurities found in the Novillo tokamak.

The numerical study of the divers magnetic field configurations in the Novillo Tokamak developed by means of the CAMTOK code is presented to illustrate not only the application of classical analysi...

To search for the absorption of deuterium gas in titanium plates and the neutron emission from this process, electrical discharges between two titanium electrodes in a deuterium atmosphere have been performed. During the discharges, a temperature >300°C on the surface of the electrodes was measured. A typical characteristic of the phenomenon observed was the deuteration of the electrodes. Pressure reduction was notorious when the chamber was previously cooled with liquid air. Deuterium absorption seemed to be present in all experiments whether or not liquid air was added on the deuteration chamber. Sheets of CR39 plastic detectors, a Bonner sphere, and a fission chamber were used to look for neutron emission.