Evaluation of the Sub Acute Toxicity of the Stem Bark of Andira inermis

The aqueous methanolic Andira inermis stem bark extract was screened in evaluation of its potential for its toxic effect in a 28 days study using the oral route only. The sub acute study was carried out in Wistar rats divided into 4 groups of 5 rats each; control group (a) received distilled water while the aqueous methanolic Andira inermis stem bark extract treatment groups (b), (c), and (d), received 100, 200, and 400 mg/kg of the extract respectively, for a period of 28 days, with their intake of feeds, water and signs of abnormality observed. At the end of the sub acute study, the rats were anaesthetized with chloroform and blood collected by cardiac puncture for biochemical and haematological evaluation. And the visceral organs (liver, kidneys, lungs, heart and spleen) excised for weighing and patho-morphological examination. The aqueous methanolic Andira inermis stem bark extract was found to; reduce the intake of water weekly, drop intake of feeds; significantly increased the red blood cell count (RBC), the haemoglobin concentration (HB), as well as the pack cell volume (PCV). The renal indices, showed the electrolytes sodium and chloride of the treatment groups (b, c and d) to be significantly different from the control. Urea was noticed to have reduce significantly and creatinine insignificantly. The organs weights across the Andira inermis treatment groups were noticed to be insignificantly (P › 0.05) different from the control for all the organs sampled (Lungs, Liver, Heart and Spleen) except for the kidney (organ weight which was noticed to have increased significantly). The patho-morphologies of the organs showed the heart to be normal, the kidney was normal in the control and the other treatment groups 100 mg 400 mg and 200 mg but a rat (an outlier) in one of the 200 mg group was noticed with tubular necrosis; the liver indicated a non concentration-dependent hepatitis while the lungs and the spleen presented an infective process. It was concluded that, the aqueous methanolic extract of Andira inermis is a safe medicinal plant with the capacity to; raise red blood cell count (RBC), haemoglobin concentration (HB) as well as the pack cell volume (PCV); proffers a nephro- protective property; shrunken spleen; have a hepato-protective property and as well was non toxic to the heart and lungs. These findings warrants further pharmacognostic efficacy experimental research to harness the array of benefits of Andira inermis as discovered in this study.

Effect of Chloride Ions on the Electrochemical Oxidation of Chalcopyrite at 340 °C and 21 MPa

Understanding the oxidative mechanisms of chalcopyrite in various hydrothermal fluids is of great significance to improve copper extraction and to model the geochemical cycling of copper, iron, and sulfur. This paper investigated the effect of NaCl on the electrochemical oxidation of chalcopyrite at 340 °C and 21 MPa using polarization curves, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and Raman spectroscopy. The experimental results showed that NaCl can promote chalcopyrite leaching. As NaCl concentration increases, the protective property of the oxidation layer degraded. In the absence of NaCl, the oxidation layer that consisted of CuSn, (n ≥ 1), probably with some Fe2O3 and Fe(OH)3 and also in the presence of NaCl, Fe2O3, is the principal oxidation product. More rapid ionic diffusion and further chemical reaction contributed to the improvement of chalcopyrite dissolution with increasing NaCl concentration. A dissolution mechanism is proposed in this paper to explain the chalcopyrite leaching processes which is dependent on NaCl concentration.

Polyurethane/Zinc Oxide (PU/ZnO) Composite—Synthesis, Protective Property and Application

A polyurethane (PU) is a multifunctional polymer prepared by using more than two types of monomers. The unique properties of PU come from monomers, thus broadening the applicability of PU in many different sectors. The properties can be further improved by using many nanoparticles. Different metal oxides as nanoparticles are also widely used in PU materials. ZnO is a widely used inorganic metal oxide nanoparticle for improving polymer properties. In this review article, the techniques to prepare a PU/ZnO composite are reviewed; the key protective properties, such as adhesive strength and self-healing, and applications of PU/ZnO composites are also highlighted. This review also highlights the PU/ZnO composite’s current challenges and future prospects, which will help to broaden the composite practical application by preparing environmentally friendly composites.