Antinociceptive properties and acute toxicity of ethanol extract of Bromelia laciniosa Mart. ex Schult. f. (Bromeliaceae)

Purpose: To investigate the antinociceptive activity and acute toxicity of the ethanol extract of Bromelia laciniosa leaf.Methods: A high performance liquid chromatography HPLC fingerprint of phenolic compounds was developed. The antinociceptive effect of ethanol extract (Bl-EtOH) in mice was carried out using chemical (writhing and formalin) and thermal (hot plate) models of nociception. The acute toxicity of the extract was performed in mice using doses of 2.0 g/kg intraperitoneally and 5.0 g/kg orally. Blood was removed for laboratory analysis of hematological and biochemical parameters.Results: Bl-EtOH (100, 200 and 400 mg/kg, i.p.) reduced the number of writhing (91.80, 93.44 and 78.68 %, respectively) and the number of paw licks during the first (60.86, 62.84 and 66.79 %) and second phase (91.93, 82.18 and 88.73 %) of the formalin test. Naloxone (1.5 mg/kg, i.p.) antagonized the antinociceptive action of Bl-EtOH (100 mg/kg), and this finding suggests involvement of opioid mechanism. The effect of Bl-EtOH on hot plate response provides a confirmation of its central effect.Conclusion: B. laciniosa leaf extract has antinociceptive properties. Peripheral, and at least in part, central mechanisms, may be involved in this antinociceptive effect. The ethanol leaf extract apparently presents no significant toxicity.Keywords: Bromelia laciniosa, Nociception, Pain, Writhing, Acute toxicit

Graded plasma spraying of premixed metal-ceramic powders on metallic substrates

The mismatch between the thermal expansion coefficients of ceramics and metals and the differential stresses it causes at the interface create problems in metal to ceramic joining, Research has been conducted to solve this problem in thermal barrier coating technology. Previous studies have considered metal-ceramic multilayers or graded-coatings, which include a metallic bond coat. In this study, a graded plasma-sprayed metal-ceramic coating is developed using the deposition of premixed metal and ceramic powders without the conventional metallic bond coat, Influences of thickness variations, number, and composition of the layers are investigated. Coatings are prepared by atmospheric plasma-spraying on Inconel 718 superalloy substrates. Ni-Cr-Al and ZrO2-8% Y2O3 powders are used for plasma spraying, Adhesive and cohesive strength of the coatings are determined. The concentration profile of the elements is determined by x-ray energy-dispersive analysis. The microstructure and morphology of the coatings are investigated by optical and scanning electron microscopy (SEM). Results show that the mixed metal-ceramic coating obtained with the deposition of premixed powders is homogeneous. The morphology and microstructure of the coatings are considered satisfactory.6219920

Elastic positron scattering by C2H2: Differential cross sections and virtual state formation

We present calculated elastic differential cross sections for positron-acetylene scattering, obtained by using the Schwinger multichannel method. Our results are in very good agreement with quasielastic experimental data of Kauppila [Nucl. Instrum. Meth. Phys. Res. B 192, 162 (2002)]. We also discuss the existence of a virtual state (zero-energy resonance) in e(+)-C2H2 collisions, based on the behavior of the integral cross section and of the s-wave phase shift. As expected the fixed-nuclei cross section and annihilation parameter (Z(eff)) present the same energy dependence at very low impact energies. As the virtual state energy approaches zero, the magnitude of both cross section and Z(eff) are extremely enhanced (at zero impact energy). The possibility of shifting from a low-lying virtual state to a shallow bound state is not expected to significantly affect room-temperature annihilation rates.68

WAsP model performance verification using lidar data

© 2015, The Author(s).This study describes the verification of Wind Atlas Analysis and Application program (WAsP) modelled average wind speeds in a complex terrain. WAsP model was run using data collected at 3 masts: Kalkumpei, Nyiru and Sirima using cup anemometers and wind vanes for the entire 2009 calendar year and verified using data collected by WindTracer LIDAR (light detection and ranging) for 2 weeks from 11th to 24th July 2009. Evaluating WAsP mean wind speed map using LIDAR data showed that Nyiru station provides the best data to model mean wind speed over the wind farm domain with a mean difference of 0.16 m/s, root mean square error of 0.85 m/s and Index of Agreement of 0.61. Construction of a 310 MW windfarm has commenced at this site. Once completed, the windfarm will be operating 365 vestas V52-850kW turbines