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Ikot-Ekpene, Nigeria

Solomon M.M.,University of Uyo | Umoren S.A.,King Fahd University of Petroleum and Minerals | Abai E.J.,Akwa Ibom State Polytechnic
Journal of Molecular Liquids | Year: 2015

Poly(methacrylic acid)/silver nanoparticles (PMAA/AgNPs) composite was prepared in-situ and characterized by UV-vis spectroscopy, FTIR, TEM, XRD, and EDS. The anticorrosion performance of the composite was investigated by gravimetric, electrochemical, SEM, EDS, and water contact angle measurements. Results obtained show that PMAA/AgNPs act as corrosion inhibitor for mild steel in 0.5 M H2SO4 solution. Inhibition efficiency increased with increase in concentration and temperature. PMAA/AgNPs composite behaved as a mixed-type corrosion inhibitor and adsorption onto the metal surface followed Temkin adsorption isotherm model. Results from all the surface analyses confirm the formation of PMAA/AgNPs protective film on the mild steel surface. © 2015 Elsevier B.V. Source

John R.C.,University of Uyo | Itah A.Y.,University of Uyo | Essien J.P.,University of Uyo | Ikpe D.I.,Akwa Ibom State Polytechnic
Bulletin of Environmental Contamination and Toxicology | Year: 2011

The effect of crude oil on the growth of legumes (Calopogonium muconoides and Centrosema pubescens) and fate of nitrogen-fixing bacteria in wetland ultisol was investigated using standard cultural techniques. The results revealed observable effects of oil on soil physico-chemistry, plant growth and nodulation as well as on densities of heterotrophic, hydrocarbonoclastic and nitrogen fixing bacteria. The effects however varied with different levels (0.5%, 1%, 5%, 10%, 15% and 20%) of pollution. Ammonium and nitrate levels were high in the unpolluted soil but decreased with increase in pollution levels. Nitrite was not detected in contaminated soil probably due to the reduction in numbers of nitrogen fixers, from 5.26 ± 0.23 × l0 6cfu/g in unpolluted soil to 9.0 ± 0.12 × 10 5 and 2.2 ± 0.08 × l0 5 cfu/g in soils with 5% and 20% levels of pollution respectively. The contaminated soil also exhibited gross reduction in the nodulation of legumes. A range of 13-57 nodules was observed in legumes from polluted soil against 476 nodules recorded for plants cultured on unpolluted soil. The heterogeneity of the microbial loads between oil-polluted and unpolluted soil were statistically significant (p<0.05, ANOVA). Positive significant relationships were observed between the levels of hydrocarbons and the densities of heterotrophic bacteria (r = 0.91) and that of hydrocarbon utilizing bacteria (r = 0.86). On the other hand, relationships between the densities of nitrogen fixing bacteria and total hydrocarbons content was negative (r = -0.30) while positive relationships were recorded between the densities of different microbial groups and treatment periods except at 15% and 20% pollution levels. The LSD tests revealed highly significant differences (p<0.001) in the physiological groups of soil microorganisms at all levels of pollution. The results imply that crude oil seriously affects rhizosphere microbial growth in legumes. Among the bacterial species isolated, Clostridium pasteurianum, Bacillus polymyxa and Pseudomonas aeruginosa exhibited greater ability to degrade hydrocarbons than Azotobacter sp, Klebsiella pneumoniae and Derxia gummusa while Nitrosomonas and Nitrobacter had the least degradability. A continuous monitoring of the environment is advocated to prevent extinction of nitrogen-fixing bacteria and total loss of soil fertility attributable to petroleum hydrocarbon contamination in the Niger Delta ultisol. © The Author(s) 2011. Source

Ekaluo U.B.,University of Calabar | Ibiang Y.B.,University of Calabar | Ikpeme E.V.,University of Calabar | Ekanem B.E.,Akwa Ibom State Polytechnic | Erem F.A.,University of Calabar
Toxicology and Environmental Health Sciences | Year: 2013

This study was undertaken to determine the effects of Deltamethrin and Ridomil, singly and in combination, on epididymal sperm parameters and reproductive hormone levels of male rats. Thirty two albino rats were divided into four independent treatment groups; A, D, R and C. Group A was the control and did not receive any pesticide treatment. Groups D (100 mg of Deltamethrin/kg body weight), R (100 mg of Ridomil/kg body weight) and C (50 mg Deltamethrin+50 mg Ridomil/kg body weight) received pesticide treatment at forty eight hour intervals for nine weeks, via direct mixing in the animal ration. After nine weeks the animals were sacrificed, blood was collected and epididymal sperm parameters were assessed. Significant (P<0. 001) decreases were observed in sperm count and sperm motility between the control and groups D and C. Sperm viability, sperm head abnormality and pH of semen did not reveal any significant differences (P<0. 05). Follicle stimulating hormone and luteinizing hormone showed significant (P<0. 01) decreases in groups D and C, but no significant differences were observed in testosterone levels. Deltamethrin, and Deltamethrin+Ridomil combination decreased sperm count, sperm motility, and serum gonadotropins of the rats. © 2013 Korean Society of Environmental Risk Assessment and Health Science and Springer Science+Business Media Dordrecht. Source

Okokon J.E.,University of Uyo | Udoh A.E.,University of Uyo | Frank S.G.,Akwa Ibom State Polytechnic | Amazu L.U.,University of Nigeria
Asian Pacific Journal of Tropical Biomedicine | Year: 2012

Objective: To evaluate the anti-inflammatory and analgesic activities of leaf extract of Melanthera scandens (M. scandens). Methods: The crude leaf extract (39-111 mg/kg) of M. scandens was investigated for anti-inflammatory and analgesic activities using various experimental models. The anti-inflammatory activity was investigated using carragenin, egg-albumin induced oedema models, while acetic acid, formalin-induced paw licking and thermal-induced pain models were used to evaluate the antinociceptive property. Results: The extract caused a significant (P<0.05 - 0.001) dose-dependent reduction of inflammation and pains induced by different agents used. Conclusions: The leaf extract possesses anti-inflammatory and analgesic effects which may be mediated through the phytochemical constituents of the plant. Source

George N.J.,Akwa Ibom State Polytechnic | Obot I.B.,University of Uyo | Ikot A.N.,University of Uyo | Akpan A.E.,University of Calabar | Obi-Egbedi N.O.,University of Ibadan
E-Journal of Chemistry | Year: 2010

The phytochemistry of Achornea cordifolia leaf extract using different solvents was studied using standard methods. The effects of the leaf extract on some pathogenic bacteria and fungi were also examined. The Phytochemical screening of the leaves shows the presence of useful ethno-botanical bioactive substances such as tannin, saponin, flavonoid, cardiac glycoside and anthraquinone, while alkaloid, phlobatanin and terpene also tested for were absent. The butanol fraction of the extract gives the highest zone of inhibition (13.0 mm) against Staphylococcus aureus, Escherichia coli and pseudomonas aeruginosa, which are in parity. The control, gentamycin injection gives 12.5 mm, 11.0 mm and 12.0 mm respective zones of inhibition against the Staphylococcus aureus, Eschariclia coli and Pseudomonas aeruginosa. Also, the butanol fraction of the extract shows highest zone of inhibition of 17.0 mm against Candida albican, while ethanolic extract gives 13.0 mm zone of inhibition against Trichophyton violaceum. Source

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