Search

In this research, the applicability of maghemite (γ-Fe3O4) nanoparticle enriched with pistachio nut shell activated carbon (PCNS-AC) for the separation of Ni (II) ions from aqueous solution was investigated. The γ- Fe3O4 nanoparticles were synthesized using a sol-gel method. The γ-Fe3O4 nanoparticles of the adsorbent were characterized by surface area Brunauer, Emmett and Teller (BET), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Fourier transform infrared (FTIR) spectroscopy and the zero point charge (pHZPC). The adsorption isotherm data were analyzed using the Langmuir, Freundlich, Redlich- Peterson, and Koble-Corrigan models. The best fit for the equilibrium process was the Koble-Corrigan model. The kinetic studies indicate that the adsorption follows the pseudo-second-order kinetics. The rate of adsorption improves with increasing temperature, and the process is endothermic with ΔH value of 196.87 kJ mol-1. The activation energy of the adsorbent was calculated to be 519.62 kJ mol-1. The results also reveal that γ-Fe3O4-PCNS-AC from agriculture biomass can be an attractive option for metal removal from industrial effluent. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the antihypertensive activity of aqueous extracts obtained from Malaysian coastal seaweeds and to determine the pharmacological mechanisms of the extracts on rat aorta in vitro. Materials and Methods: The antihypertensive activity of 11 species of seaweeds (5 brown, 1 red and 5 green algae) were tested by cumulative addition of the extracts to phenylephrine (PE)-precontracted Wistar-Kyoto (WKY) aortic rings in in vitro isometric contraction studies. Mechanisms for vasorelaxant effect were investigated in the presence of various antagonists. Results: Of the 11 species tested, 2 showed a vasorelaxant effect. Further investigation of the mechanisms of action of the aqueous extract of green alga, Cladophora patentiramea (AECP),showed that the vascular relaxant effect was endothelium- and concentration-dependent. A maximum relaxation of 45.8 ± 4.6% (n = 8, p < 0.001) was obtained at 0.1 mg/ml of extract, after which the response was found to reduce in a concentration-dependent manner to 15.7 ± 4.9% (n = 8, p < 0.001) at the highest extract concentration tested. Pretreatment of endothelium-intact aortic rings with Nω-nitro-L-arginine methyl ester (L-NAME, 30 μM), 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ, 10 μM) and methylene blue (100 μM) resulted in a complete blockade of AECP-induced vasorelaxation. However, the relaxant effects of the extract were not blocked by atropine (1 μM), indomethacin (10 μM) and glibenclamide (10 μM), although the maximum relaxant responses were enhanced in the presence of glibenclamide. Conclusion: Our data showed that the in vitro vascular relaxant effect of AECPwas mediated through endothelium-dependent nitric oxide-cGMP pathway, and was not associated with the release of vasodilator prostaglandins, activation of muscarinic receptors, or ATP-sensitive potassium channels opening. Copyright © 2010 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]