273 research outputs found
Adsorption Behaviour of [(4-Hydroxy-6-methyl-2-oxo-2Hpyran- 3-yl)-(4-methoxy-phenyl)-1methyl]-urea on Stainless Steel in Phosphoric Media
The adsorption of [(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)-(4-methoxy-phenyl)- methyl]-urea on iron in phosphoric media was studied by using electrochemical
technique. The adsorption mechanism was investigated using adsorption isotherms. The experimental data fit localized adsorption models. The values for free energy of
adsorption, o DGads , were also calculated at each surface coverage, �, of the studied compound by applying the mathematical model of Bockris – Swinkels adsorption
isotherm. The variation of free energy of adsorption o
ads DG with surface coverage, �, was interpreted in terms of deviation from ideal condition assumed in Langmuir model. A possible adsorption model of HPU2 molecules on to the metal surface was suggested
Synthesis, characterization, antimicrobial activity and toxicology study of some metal complexes of mixed antibiotics
Mixed ligand metal complexes of ampicillin and chloramphenicol prepared by using Ni(II), Co(II) and
Fe(III) metal chloride hexahydrate were reported and characterized based on some physical properties
and spectroscopic analysis such as AAS, UV, and IR spectroscopy. The complexes were proposed to
have the formulae [ML1L2](Cl)n ( where M= Ni(II), Co(II), Fe(III); L1 = ampicillin, L2 = chloramphenicol, and
n=2-3). IR spectra suggested that both L1 and L2 coordinated to the metal ions in a terdentate manner
with �(O-H), �(C=O) and �(N-H) as donor sites in each of the ligands. From analytical and spectroscopic
data obtained, the complexes were proposed to be of octahedral. The synthesized complexes, in compares to their ligands, were also screened for their antibacterial activity against isolated strains of Escherichia coli, Staphylococcus aureus and Klebsiella pneumonia by using agar diffusion method.
The activity data showed the metal complexes to be more potent antibacterial than the parent drugs against the three bacteria species. However, toxicology tests against some tissues of albino rat (Rattus novergicuss) revealed toxicity of the complexes as compared to the parent drugs because the complexes were found to significantly increase (P<0.05) alkaline phosphatase from homogenates of
liver and kidney tissues of the tested doses. However, there was no significant difference (P>0.05) in
ALP of rat serum. The results generally indicated that more potent compounds with better physical properties and enhanced antimicrobial activities upon complexation have been prepared
Fe(III) and Co(II) complexes of mixed antibiotics: synthesis, characterization, antimicrobial potential and their effect on alkaline phosphatase activities of selected rat tissues
Two new mixed ligand metal complexes of Fe(III) and Co(II) chloride hexahydrate salts were prepared using standard methods. Ampicillin trihydrate and oxytetracycline hydrochloride antibiotics were used as ligands. Chemical analysis including conductivity measurements, molecular weight determination and spectroscopic studies were used to propose the geometry and mode of binding of the ligands to
metal ions. Both ligands were proposed to coordinate to metal ions in ratio 1:1:1 in the complexes.
Each of the ligands acted as terdentate ligand. Inhibition properties as well as toxicity effect of administration of the metal complexes at the dose of 3.33 mg/kg body weight thrice daily for 5 days on the alkaline phosphatase (ALP) activities on rat kidney, liver and serum were evaluated. The inhibitory properties of the complexes were found to be significantly different (P<0.05) at the concentration of
1%(w/v) as compared to each of the ligands. The complexes were found to significantly increase (P0.05) in ALP from liver and kidney sera. The results indicated that more potent compounds with better physical properties and enhanced antimicrobial
activities upon complexation have been prepared
Facile Synthesis and Characterization of New 2,3-Disubstituted Benzimidazole Derivatives
Benzimidazoles are known to represent a class of medicinally important compounds which are extensively used as antibacterial agents. Hence, a series of five 2-substitutedbenzimidazole precursors (1a-e) were synthesized via [4 + 1] condensation and imino compound (1f) by simple condensation in the presence of Conc. HCl as catalyst. Synthetic modification of N-1 position was achieved in order to obtain new 5-chloro-2,4-dinitrophenyl bearing 1,2-disubstituted benzimidazole 2a-e and 2f, and 3-chlorobenzyl bearing 1,2-disubstituted benzimidazole 3a-e and 3f in good to excellent yields using a facile approach. The chemical structures of all synthesized compounds were confirmed using spectroscopic means such as UV-visible, IR, Mass spectra, 1H and 13C NMR as well as C, H, N elemental analytical data
Synthesis, physical properties, antimicrobial potentials of some mixed antibiotics complexed with transition metals and their effects on alkaline phosphatase activities of selected rat tissues
Mixed ligand metal complexes of chloramphenicol and oxytetracycline were prepared by using Ni(II), Co(II) and Fe(III) metal chloride hexahydrate. They were characterized based on some physical technique and spectroscopic analysis such as AAS, UV, and IR spectroscopy. Based on the analytical and spectroscopic data, the complexes were proposed to have the formulae [ML1L2](Cl)n (where M =
Ni(II), Co(II), Fe(III); L1 = chloramphenicol, L2 = oxytetracycline and n = 2 - 3). IR spectra suggested that
both L1 and L2 coordinated to the metal ions in a terdentate manner with �(O-H), �(C=O) and �(N-H) as
donor sites in each of the ligands. The complexes were proposed to be of octahedral. The synthesized complexes, in compares to their ligands, were screened for their antibacterial activity against isolated strains of Escherichia coli, Staphylococcus aureus and Klebsiella pneumonia by using diffusion method. The activity data showed the metal complexes to be more potent antibacterial than the parent drugs against the three species. Toxicology tests against some tissues of albino rat (Rattus
novergicuss) revealed toxicity of the complexes as compared to the parent drugs. Ni(II) complex was found to possess no significant difference (P > 0.05) in alkaline phosphatase from both homogenates of liver and kidney and rat serum. However, Co(II) and Fe(III) complexes were found to significantly increase (P < 0.05) alkaline phosphatase from homogenates of liver and kidney tissues of the tested
doses but there was no significant difference (P > 0.05) in alkaline phosphatase from rat serum
Influence of Metolachlor on Physiological Growth Character of Tomato (Lycopersicon esculentum L.)
A field trial was carried out to investigate the effects of various concentrations (0, 1, 2, 3kg.a.i/ha) of metolachlor on physiological growth character of tomato. Results of this study showed that weeds were decreased in proportion to applied concentration of metolachlor. Metolachlor at 3kga.i/ha did not improve physiological growth character of tomato in spite of effective weed reduction. Tomato leaf area ratio (LAR) declination with age was higher in the plots sprayed with metolachlor at 1-2kg.a.i /ha than those obtained in the weedy control plots. The relative growth rate (RGR) and net assimilation rate (NAR) of tomato in the weedy control plots were adversely affected as from 6th week after transplanting .This period coincides with high weed density. However, the relative growth rate (RGR) and net assimilation rate (NAR) of tomato in plots sprayed with metholachlor at 1-2kg.a.i/ha showed vigorous growth till 7th week after transplanting(WAT) before showing declination. These results suggest that metolachlor at 1-2kg.a.i/ha could be an effective and safe herbicide for application in transplanted tomato
Microwave-Assisted Synthesis and Antibacterial Activity of some Pyrazol-I-Ylquinoxalin-2(IH)-One Derivatives
3-Hydrazinoquinoxalin-2(1H)-one was prepared from quinoxaline-2,3-dione and subsequently used for the synthesis of some potentially biologically active 3-(pyrazol-1-ylquinoxalin-2(1H)-one derivatives. While 3-(3,5-dimethylpyrazol-1-yl)quinoxalin-2(1H)-one showed a comparative effect with streptomycin, 3-(5-oxo-3-phenyl-4,5-di- hydropyrazol-1-yl)quinoxalin-2(1H)-one was found to be the most active at MIC value of 7.8 μg/m
IMPACT OF BANKING CONSOLIDATION ON THE PERFORMANCE OF THE BANKING SECTOR IN NIGERIA
Following the consolidation of the Nigerian banking sector in 2005, to among other things, develop a strong and reliable banking sector capable of supporting the development of the domestic economy, this paper examines the performance of the programme by comparing the pre- and post-consolidation performance of the sector. Two independent samples representing the 9-year period preceding the 2005 banking consolidation exercise and the corresponding 9-year post consolidation period were analyzed. Performance assessment indicators analyzed in the study are non-performing loans ratio (asset quality), return on assets (earnings/profitability), capital adequacy ratio (long-term liquidity) liquidity ratio (short-term liquidity), bank loans and advances ratio (credit delivery) and bank assets ratio (bank size). Levene's independent sample t-test was used to determine evidence of significant difference in banking sector performance between the pre- and post-consolidation periods. At 5 per cent level of significance, the study shows evidence of significant differences in asset quality, capital adequacy ratio and loans and advances ratio. However, there is no evidence that return on assets, liquidity ratio and bank asset ratio differ significantly between the pre- and post- consolidation periods. Based on the above results, we conclude that banking consolidation significantly impacted on banking sector performance in Nigeria. We therefore recommend introduction of adequate regulatory measures, by the relevant authorities, in the sector as well as implementation of robust human capital development initiatives as imperatives for nurturing and sustaining the gains of the exercis
CLIMATIC CHANGE AND PESTICIDES USAGE: A BRIEF REVIEW OF THEIR IMPLICATIVE RELATIONSHIP
Pesticides are very important for the prevention, mitigation, destruction of pests and diseases for the improvement of agricultural efficiency due to their contributions to agricultural yields and improving the standard of living. Considering the dynamicity and influence of weather in our everyday lives, it is obvious that the effects of pesticides might also be a contributing factor and vice versa. Climate change could have an influence on both pesticides’ usage, as well as the losses of pesticides to the environment. Presently, the issue of climate change is one of the furthermost intellectual challenging issues facing the entire human race. Therefore, we must continue to protect our environment from these unfavorable effects of climate change by extremely dipping the emissions of greenhouse gases especially via the use of chemical substances such as pesticides. In this review study, we will briefly attempt to give an insight and try to bridge the uncertainty surrounding the effects of the use of pesticides and its relationship to climate change effects on the environment
Physical characterisation of some honey samples from North-Central Nigeria
Some physicochemical properties (water content, sugar content, viscosity, pH and conductivity) were
determined for honey samples from North-Central Nigeria to evaluate their global behaviour and
comparison with other honey samples. The water content and sugar content varied within the range of
(18.22 - 36.82%) and (63.82 - 80.25%) respectively. The pH increased with increase in water content and
the conductivities of the samples had correlation with proportion of minor constituents in the honey
samples. The relationship among water content (w), temperature (t) and viscosity (�) for different honey
samples of may be represented as � = 17.678× 10
3
exp (-0.32w - 0.088t). The temperature dependence of
viscosity was evaluated with Arrhenius model, the activation energy with value of 70.07 kJ/g is fairly
unaffected by moisture content
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