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A mathematical framework that provides practical guidelines for user adoption is proposed for fuel cell performance evaluation. By leveraging the mathematical framework, two measures that describe the average and worst-case performance are presented. To facilitate the computation of the performance measures in a practical setting, we model the distribution of the voltages at different current points as a Gaussian process. Then the minimum number of samples needed to estimate the performance measures is obtained using information-theoretic notions. Furthermore, we introduce a sensing algorithm that finds the current points that are maximally informative about the voltage. Observing the voltages at the points identified by the proposed algorithm enables the user to estimate the voltages at the unobserved points. The proposed performance measures and the corresponding results are validated on a fuel cell dataset provided by an industrial user whose conclusion coincides with the judgement from the fuel cell manufacturer.

The leaves of Moringa oleifera were subjected to ethanol extraction. The extract was fractioned and patitioned using different organic solvents in order of increasing polarity. Standard methods were used for both extraction and phytochemical screening. Modified agar well diffusion method was adopted for screening the antimicrobial activities of the leaf extracts. The test was carried out in triplicates. The extract was phytochemically screened and revealed the presence of Flavonoid, Alkaloid, Tannins, Steroid, Saponins, Cardic glycosides, Terpenoids, Anthraquinone. The chloroform extract at 100 mg / ml concentration showed highest antimicrobial activity of 18mm on both gram positive and gram negative organisms (S. aureus, P. mirabilis and P. vulgaris) and 17mm on P. auriginosa, E. coli and K. pneumoniae. However it had 16mm on S. epidermidis and 14mm on C.albicans. The aqueous extract had strong antimicrobial activity (17mm, 14mm, 14mm, 14mm, 13mm, 13mm, 13mm and 12mm, on S.aureus, P.auriginosa, E. coli, K. pneumoniae, P. mirabilis, P. vulgaris, S.epidermidis, and C.albicans respectively). Ethyl acetate extract showed moderate antimicrobial activity of 13mm, 12mm, 15mm, 13mm, 14mm, 13mm, 13mm and 12mm on S. aureus, S.epidermidis, P.auriginosa, E. coli, K. pneumoniae, P. mirabilis, P. vulgaris and C. albicans respectively. n-hexane extract had the least antimicrobial activity of 14mm, 12mm, 14mm, 14mm, 13mm, 12mm, 12mm and 12.5mm on S.aureus, S.epidermidis, P. auriginosa, E. coli, K.pneumoniae, P. mirabilis, P. vulgaris and C. albicans respectively. The 50mg/ml and 25mg/ml extract’s concentrations had lesser diameter zones of inhibitions in decreasing order of the decreasing concentrations.The extracts were subjected to MIC evaluation and the findings of the chloroform extract showed that S. aureus was the most sensitive; followed by E. coli, K. pneumoniae, followed by P. auriginosa, P. mirabilis, P. vulgaris, S. epidermidis and C. albicans. The MBC showed no value. This study proved that the leaves of M. oleifera contain some active principles with antimicrobial activity and could enhance its use in preventing and curing diseases, when purified to the appropriate pharmacological level.Keywords: M. oleifera, Phytochemical, Antimicrobial, Infectious isolates

The leaves of Mangifera indica were subjected to ethanol extraction and the extracts fractioned by suspending the extract in 20% ethanol and partitioned with different organic solvents (n-hexane, chloroform, ethyl acetate) in order of increasing polarity. Standard methods were used for both extraction and phytochemical screening. Modified agar well diffusion method was adopted for screening the antimicrobial activities. The test was carried out in triplicates. The test organisms were S. aureus, S. epidermidis, P. aeruginosa, E. coli, K. pneumoniae, P. mirabilis, P. vulgaris and C. albicans. The leaf extract was phytochemically screened and revealed the presence of Flavonoid, Alkaloid, Tannins, Steroid, Saponins, Cardiac glycosides, Anthraquinone, Triterpenoids. The chloroform leaf extract showed strong antimicrobial activity on both gram positive and gram negative organisms; followed by the aqueous extract. The ethyl acetate leaf extract ranked third. n-hexane leaf extract had the least antimicrobial activity. The 100 mg/ml concentration exerted a broad spectrum antimicrobial activity with the highest diameter zone of inhibition of 18mm against Staphylococcus aureus and Klebsiella pneumoniae. This activity was followed by the 50 mg/ml and 25 mg/ml concentrations in that order. Fifty (50) mg/ml exerted the diameter zones of inhibitions of 10.5 mm while 25 mg/ml concentrations exerted the diameter zones of inhibitions of 7.5 mm. Also the least antimicrobial activity was exerted by the 25 mg/ml concentration, followed by the 50 mg/ml concentration with diameter zones of inhibitions of 4 mm and 7.5mm respectively, against S. epidermidis and C. albicans and some Gram negative organisms. The data obtained showed broad spectrum activities with increasing diameter zone of inhibitions at increasing concentrations, which showed that the inhibitory effects of the extracts were not only solvent dependent but also concentration dependent (Figures 1 – 8). The extracts were subjected to MIC evaluation and the findings showed that E. coli and K. pneumoniae were the most sensitive. The MBC showed no value. This study shows that the leaves of M. indica when purified to the appropriate pharmacological level, contain some active principles with antimicrobial potential that will be useful in preventing and curing diseases.Keywords: M. oleifera, Antimicrobial, Phytochemical, Infectious isolates

Microcrystalline cellulose (MCC) obtained from the fresh stem of Laccosperma opacum (Rattan) found in coastal region of Niger Delta forest zones of West Africa was investigated to ascertain its microbiological standard for use as a potential pharmaceutical excipient. The product, coded LO-MCC, was prepared by treating alpha–cellulose obtained from stalk of Laccosperma opacum (in pulp form) with 2.5 N hydrochloric acid followed by bleaching with 0.1N sodium hypochlorite heated to 50oC for 30 min. The product obtained was assessed for its microbiological quality and comparatively evaluated with those of fine grade MCC (Avicel PH 101) for its physicochemical, phytochemical and micromeritic properties. Result showed a whitish, tasteless, odorless crystalline MCC powder with a yield of 24.17%. Angle of repose 41±0.03o, bulk volume 82± 0.94 ml, tapped volume 52± 0.9 ml, bulk density 0.25 g/mL, tapped density 0.39 g/mL, Hausner ratio 1.59 and Carr’s compressibility index 46.7. Swelling index, moisture sorption and hydration capacities of 1.58, 0.83 and 6.46 respectively were obtained. Microbiological evaluation indicates absence of yeast, fungi as well as coliform and other objectionable bacteria. These indicate that LO- MCC complied with the minimum bioburden standard for raw materials from natural origin; its potential as disintegrant and vehicle for direct compression in tableting was evident.Keywords: microcrystalline cellulose (MCC) Laccosperma opacum, micromeritic, Microbiological quality, Physicochemical properties, Phytochemical constituents, Physicotechnical properties

A simple colorimetric assay for field estimation of chloroquine in tablet dosage forms and biological fluids would be useful, given that the high prevalence of substandard brands may have been a factor in the development of drug resistance. Chloroquine base was liberated from chloroquine phosphate tablets and extracted with chloroform. Methyl orange was then used to complex the base and the absorbance of the complex was determined in a colorimeter. This method was used in determining the amount of drug in tablet brands and urine samples of volunteer human subjects. It was able to determine the amounts of chloroquine in the tablets, with only two tablet brands out of 5 passing the test for content of active ingredient. Statistical analyses of the results show that there are significant differences in chloroquine elimination in the volunteers in each group (p = 0.005 and 0.004 for groups 1 and 2 respectively). An initial (36 h) elimination half life of 22.88 ± 6.93 was obtained. This value agrees significantly with initial plasma elimination half life of chloroquine reported in literature. This test may therefore be a good quality-indicating assay for resource limited or field conditions. Keywords: chloroquine, colorimetry, methyl orange, complexation, assay

Objectives: To evaluate if low dose oral Ketamine has oxytotic effect on term pregnant uterus.Methodology: This is a cross sectional double blind placebo control prospective study. A total of 745 parturients were studied, 261 had low dose oral Ketamine in active phase of labour (group A), 227 had Oxytocin augmentation (group B) and 257 had none of these medication (control group C). Their age, parity, gestational age, duration of labour and APGAR score were determined and all data analyzed using Epi Info.Results: The parturients were predominantly within the age group 26 – 35 years and their mean gestational age at delivery was 39.1weeks. The mean (± S.D.) duration of labour ( first stage of labour) was found to be shortest in group A 5.80 ± 2.06 hours, while it was 8.03 ± 3.37 hours in group B and 7.01 ± 3.25 hours in group C. Foetal outcome was comparable in all the three groups.Conclusion: Low dose oral Ketamine probably has an Oxytocic effect which needs to be explored in future research. And if this be the case, then it will be a suitable and safe single agent for labour analgesia and augmentation and for extended use in repairs of episiotomy and perineal tears.Key words: Oral Ketamine, low dose, oxytocic effect, labour duration, foetal outcome.

Purpose: To investigate the adsorptive interaction of Garcinia kola with spiramycin, since the kola is widely chewed as a tonic and spiramycin attains high concentrations in saliva.Methods: Spiramycin solutions of different concentration were added to a fixed mass of Garcinia kola (200 mg), activated charcoal or Veegum®. Shaking was carried out at room temperature after which the dispersion was filtered and the filtrate assayed for residual drug concentration. The process was repeated under different equilibrium conditions of pH and ionic strength. The adsorption data obtained for the three adsorbents were analyzed using Langmuir and Freundlich’s plots.Results: At neutral pH, drug adsorprtion by Garcinia kola, activated charcoal and Veegum® were 67, 54 and 71 %, respectively; differences in adsorption was not significant (p = 0.09). However, the other two adsorbents exhibited adverse adsorption characteristics in terms of negative adsorption capacity (-5.78 mol.kg-1) and constant (-1141 mol-1L). For each of the adsorbents, pH and ionic strength affected the extent of adsorption, due to their effect on adsorbent surface charge. Correlation with Langmuir and Freundlich relationships were poor, the correlation coefficient for the latter being 0.97, 0.894 and 0.351 for Garcinia kola, Veegum® and activated charcoal, respectively.Conclusion: The study reveals that Garcinia kola significantly adsorbs spiramycin under alkaline conditions comparable to salivary pH, and therefore should not be taken concurrently with the drug in order to minimize reduction in drug levels.Keywords: Garcinia kola, Spiramycin, Adsorption, Antidote, Interaction, Langmuir plot, Freundlich’s plot

Background: The role of water in the transmission of diarrhoea has been established. The World Health Organization (WHO) reported that diarrhoea disease were among the 10 major causes of death in young children in 11 African, Asia and South American countries. Aim: To investigate the incidence of Salmonella and Vibrio species as aetiological agents of diarrhoea in water bodies in Rivers and Bayelsa States.Methods: A total of twenty water samples were collected from rivers and cultured for the various microorganisms.The total heterotrophic counts were determined by Standard Plate Count (SPC) method. Salmonella and Vibrio species were enumerated by an enrichment procedure in Selenite F broth and Alkaline Peptone water (APW) respectively; cultured on Bismuth sulfite agar (BSA) and Thiosulphate citrate bile salt sucrose (TCBS) agar selective for salmonella and vibrio species respectively. The total coliform counts was determined and the Most Probable Number (MPN) using the multiple tube fermentation technique.Results: The study revealed isolates with various percentage occurrences which include Vibrio (12.1%) and Salmonella (33.3%). Among the coliforms were Escherichia coli (33.3%), Klebsiella (22.2%), Enterobacter (33.3%) and Citrobacter (11.1%).MPN values for enumeration of coliforms ranged from 80/100 ml to = 16,000/100 ml of the water samples analysed. Total heterotrophic count per milliliter of the original water sample ranged between 1.0 × 106 and 3.0 ×108 cfu/ml.Conclusion: The water sources examined have proved to be potential sources of diarrhoea organisms and also could lead to disease outbreak because of the significant number of these organisms in these water bodies.

The objective of the present study was to formulate disc matrices based on type B gelatin and to evaluate their potential for use as a vehicle for the delivery of isoniazid. Gelatin hydrogel was prepared in an aqueous solution and subsequently cross-linked with glutaraldehyde. The crosslinked hydrogel was cut into discs and dried under vacuum in a dessicator to form the disc-shaped matrices which were further evaluated for swelling, drug loading and in vitro drug dissolution properties. The effect of varying the duration of cross-linking time on these evaluated properties was similarly evaluated. The results obtained showed that the matrices exhibited significant swelling in simulated gastric fluid (SGF) without pepsin (pH 1.2), simulated intestinal fluid (SIF) without pancreatin (pH 6.8) as well as in water. Increase in cross-linking time resulted in increased swelling of the disc matrices in the different swelling media studied. Loading efficiency was similarly observed to increase with increase in cross-linking time with values ranging from 60 to 95 %. Release of isoniazid from the matrices was higher and more rapid in SIF than in SGF and was sustained for more than 24 h. Drug release from the formulated matrices was found to obey the Higuchi model release mechanism. This study, therefore, suggests that disc matrices based on gelatin hold some potential as a vehicle for the controlled delivery of isoniazid.Keywords: isoniazid, disc matrices, gelatine, hydrogel, cross-linkingNigerian Journal of Pharmaceutical Research, Vol. 9 No 1 pp. 1 - 14 (February 2011)

Spondias mombin leaf used traditionally in Nigeria in the management of some chronic ailments was analysed to detect and quantify its phytochemical, anti-nutrient and heavy metal contents. Following a sub-chronic oral administration of the 80 % aqueous-ethanol leaf extract at 250 and 1000 mg/kg dose levels, for 3 weeks, to Wistar albino rats, its effect on some hepatic and haematological indices was determined. This was done by in vivo assay of the levels of serum aspartate transaminase (AST), serum alanine transaminase (ALT), serum alkaline phosphatase (ALP) and serum haemoglobin (Hb) level. The phytochemical screening revealed the presence of phytates, oxalates, tannins, saponins, triterpines, glycosides and resins. Among the heavy metals, iron and aluminium were dominant, while cadmium, mercury and lead were detected at micro quantities. The levels of anti-nutrient phytate, oxalate, tannins, resins and cyanide were found to be 7.85, 2.57, 2.51, 0.40, and 0.04, percent respectively. The extract induced an inconsistent but significant increase in haemoglobin (Hb) value. There was significant decrease in serum levels of AST, ALT and ALP of rats treated with 250 and 1000 mg/kg oral doses of the extract (p < 0.05). At the upper dose, however, ALP values were slightly higher than those of the control normal animals. The findings indicated that extract of Spondias mombin at the oral dose of 1000 mg/kg is not toxic in albino rats.Keywords: Spondias mombin, haematological parameter, hepatic function indices, medicinal plantsNigerian Journal of Pharmaceutical Research, Vol. 8 No 1 pp. 183 - 187 (September 2010)

Contaminated water has been a source from which infectious diseases are spread in urban areas. Sterile sample bottles were used to collect tap water samples from eleven different locations in Enugu, capital city of Enugu State. Viable bacterial count using surface agar diffusion method was used to estimate and isolate viable organisms. Gram character, coliform count using multiple tube/most probable number technique and colony characteristics of organisms were used to arrive at our result. Bacteriological screening on all sample groups indicated the presence of microorganism in tap water available in all eleven locations. Further characterization using biochemical methods revealed the absence of E. coli, and the presence of Pseudomonas aeruginosa. Shigella species and Salmonella species in sample groups collected. Suggestions were proffered as to the methods of avoiding possible epidemic as a result of operating water supply unit which fall below WHO standards.Keywords: microbial bioload, tap water, Enugu, bacteriological screening, coliformNigerian Journal of Pharmaceutical Research, Vol. 8 No 1 pp. 56 - 61 (September 2010)

To determine the best live food and to reevaluate the optimal weaning period for beluga fish (Huso huso) larvae, seven experimental diets: Daphina (DP), Chironomids (CH), Gammarid (G), Daphina + formulated diet (DPFD), Chironomids + formulated diet (CHFD), Gammarid + formulated diet (GFD ) and formulated diet (FD) in triplicate groups were fed to 4662 sixteen-days-old larvae which were captured from the stock tank and randomly distributed into 21 tanks. The microdiets contained 48-50% crude protein, 12-13% crude fat, 9-11% moisture and 8.5-9.5% ash . After 25 days feeding trial, weight gain (WG), specific growth rate (SGR) and feed efficiency (FE) of fish fed CHFD were significantly higher than those of fish fed the other diets ( P< 0.05). Frequent cannibalism and higher mortality in larvae fed G, GFD and FD diets were observed. These results may show the importance of live food followed by formulated diets in a gradual application pattern, as early as on the fourth to fifth day after hatching.

The aim of the study is to assess the public health risk status of the potable water supply framework at the Kwame Nkurumah Postgraduate Residence (PG) Hall, University of Nigeria, Nsukka, (UNN), Enugu State, Nigeria, and environs. Four potable water supply frame-works at the PG Hall, UNN, and exposed stagnant water were sampled and analysed in accordance with the Association of Official Analytical Chemists (AOAC) Official Method of Analysis to detect their limits of chemical and microbial constituents with high public health risk. The samples comprised of tap water (A), tap-to-reservoir water (B), commercial sachet water (C) commercial bottled water (D) and exposed stagnant water (E). The nitrate levels of all the sources (except ‘B’) were above the World Health Organisation (WHO) limit (10.00 mg/L). Thus they could cause methaemoglobinemia in infants. Nitrate content of ‘B’ (6.99 mg/L) was significantly (p < 0.05) low, relative to that of ‘A’ (23.08 mg/L); and indicated microbial action. The physicochemical and microbial quality of the tap water differed significantly (p < 0.05) from that of the tap-to-reservoir water. All the pH, except that of ‘D’, were below WHO recommended pH range (6.5 to 8.5) for drinking water. ‘D’ was more or less a mineral concentrate, as its chemical constituents were significantly (p < 0.05) higher than those of other samples. Total viable count (TVC) and coli form count of the reservoir water and sachet water (0.17 to 0.20 and 0.11 to 0.09 cfu/ml, respectively), indicated heavy microbial contamination. While ‘D’, was devoid of biological contamination. Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa were among the bacteria isolated. Taken together, the sampled potable water (except ‘A’ and ‘D’) was generally, of poor chemical and microbial quality; and may be considered unacceptable.Key words: Public health risk, potable water, physicochemical and microbial water quality, water pollution.

Alpha cellulose was obtained from Costus afer and part of it was modified to microcrystalline cellulose (CAMCC). The physicochemical properties of the microcrystalline cellulose were determined and compared with those of commercial microcrystalline cellulose (Avicel 101). The swelling capacity, hydration capacity, loss on drying, true, bulk and tapped densities were 36.0 %, 5.47 %, 1.00 %, 1.198 g/ml, 0.271 g/ml, and 0.342 g/ml for CAMCC and 25.0 %, 5.10 %, 0.80 %, 1.21 g/ml, 0.291 g/ml and 0.387 g/ml respectively for Avicel 101. The CAMCC had no organic impurities, starch, and dextrins and was soluble in tetramine copper dihydroxide. It is an odourless, white, tasteless powder which conformed to the standard specification for microcrystalline cellulose. From the physicochemical properties CAMCC can act as a good disintegrant in tablet and granule formulations. Costus afer can be a good source of alpha-cellulose for pharmaceutical applicationsKeywords: Costus afer, alpha-cellulose, microcrystalline cellulose, physicochemical properties, phytochemical analysisJournal of Pharmaceutical and Allied Sciences, Vol. 7 No. 5 (2010)

Following claims of the use of the root bark of Zanthoxylum tessmannii in remedies for mouth and throat infections, particularly tonsillitis and oral thrush, it became necessary to examine the possibility of formulating the extract into lozenges. The root bark was extractedwith methanol and the phytochemical composition of the extract evaluated using standard methods. Preliminary phytochemical tests were carried out on the extract, which was then tested for activity against Candida albicans and Staphylococcus aureus, using nystatin and ampicillin/cloxacillin as control standards respectively. The extract was formulated into lozenges by dry granulation followed by compression in a tableting machine. The compressed lozenges were evaluated for friability, thickness and diameter, weight uniformityand content of active ingredient. The tests revealed heavy presence of alkaloids, flavonoids, terpenoids, oils, carbohydrates and a trace quantity of reducing sugars, tannins and steroids. The extract showed significant activity against Candida albicans in comparison with nystatin, but not against Staphylococcus aureus. The lozenges were of uniform thickness and diameter, and also conformed to the official requirements for uniformity of weight and content of active ingredient for such preparations. We conclude that the bark of the roots of Zanthoxylum tessmannii can be formulated into lozenges for oral thrush in paediatric and geriatric patients.

A binary mixture of the gums extracted from Abelmoschus esculenta (okro) and Colocasia esculenta (Cocoyam) has been evaluated for its emulsifying properties. The gums were extracted by precipitation using acetone and subjected to some physico-chemical studies. They were used both singly and in a binary mixture, as emulsifying agent in the formulation of various batches of Arachis oil emulsion. Stability studies were carried out on the formulations using parameters like creaming rate, cracking height, globule size growth and distribution, rheological changes, and influence of temperature. The physico-chemical properties confirmed the identities of the extracted hydrocolloids. Whereas okro gum possessed a better emulsifying characteristic than cocoyam gum, a combination of the gums led to an improvement in the emulsifying behaviour of cocoyam gum. Cocoyam gum can thus be used in admixture with okro gum to improve the emulsifying properties of the later. Nig. J. Pharm. Res. 3(1) 2004: 49-55

The effects of physical (pregelatinization) and chemical (acid hydrolysis) modifications on the distintegrant and dissolution properties of Tacca involucrate Starch (Tacca starch) were investigated in lactose based tablets containing 0.001% w/w of riboflavin as tracer substance, 10% w/w Tacca starch as disintegrant, 3% w/w acacia as binder, 1% w/w stearic acid as lubricant and enough quantity of lactose as diluent. The starch was incorporated intragranularly, extragranularly and intra/extragranularly. Regardless of the mode of incorporation, Tacca starch was most efficient in effecting the disintegration of the tablets and releasing their riboflavin contents in its unmodified form. In this regard, pregelatinized Tacca starch was more effective as a disintegrant than the acid hydrolysed form of the starch. Generally, fastest disintegration and dissolution were obtained with extragranular incorporation of the three forms of the starch. On the basis of dissolution efficiency values (D>E15), the modifications did not result in any retardation in riboflavin release from the tablets. Key Words: Tacca starch, pregelatinization, acid hydrolysis, extragruanular, intragranular intra/extragranular, dissolution efficiency. Bio-Research Vol.2(1) 2004: 97-102