Determination of thermal properties of some ceiling material commonly used in Ijebu- Ode, Nigeria

The study investigates the thermal properties of different insulating material used in building construction in Ijebu Ode, a tropical rainforest region, south western, Nigeria. Five insulating material; asbestos, Plaster of Paris (P.O.P), PolyVinyl Chloride (PVC), hardboard and paperboard, were subjected to thermal investigation using Lee’s disc electrical method. The result obtained showed that the thermal conductivities obtained are within the range of values specified for good insulating materials. Asbestos was found to be associated with the least thermal conductivity of the value . --while PVC had the highest thermal conductivity values of . --. This may be associated with the temperature and the heat flux on the surface of the material. The results obtained for thermal conductivity, thermal resistivity and thermal diffusivity correlated favourably when compared with those of previous work from other locations. Asbestos being the material with the lowest thermal conductivity is therefore recommended for use as the suitable insulating ceiling material in the study area. Keywords: thermal conductivity, diffusivity, resistivity, Lee’s dis

Characterization of bacteria isolates colonizing the throat of hospitalized patients at Sobi Specialist Hospital, Ilorin, Nigeria and in vitro antimicrobial effects of Citrus aurantifolia and Alum on the isolates

Background: Antibiotic resistance in microorganisms implicated in nosocomial respiratory infections is a major reason for prolonged hospital stay and increased cost of therapeutic treatment of hospital acquired pneumonia (HAP). This study was designed to isolate bacterial pathogens  colonizing the throat of hospitalized patients at the Sobi Specialist Hospital, Ilorin, and to evaluate antibacterial effects of extracts of Citrus  aurantifolia peel and Alum against these bacterial isolates. Methodology: This was a cross sectional study of 100 randomly recruited hospitalized patients at the Sobi Specialist Hospital, Ilorin, Nigeria. Throat  samples collected from consenting participants were cultured on selective agar media (MacConkey, Eosin-Methylene blue and Mannitol salt) for  isolation of bacteria. Identification of isolates from culture plates was done by Gram reaction and conventional biochemical tests while confirmation  of the isolates was done by the polymerase chain reaction (PCR) assay. Antibiotic susceptibility test for each isolate to selected antibiotics (ampicillin,  amoxicillin-clavulanate, cefuroxime, ceftazidime, gentamicin, nitrofuran, ofloxacin and ciprofloxacin) was done by the Kirby Buer disc  diffusion method. Aqueous extract of Alum ([KAl(SO4).12H2O]) was done to produce concentrations of 10, 20, 30, 40 and 50% (w/v) at pH 3.6 and  tested on the bacterial isolates using agar diffusion method. Citrus aurantifolia peel was extracted using methanol and hexane solvents to produce  extract concentrations of 500mg/ml, 250mg/ml and 150mg/ml, and tested on the isolates by agar diffusion, and by the broth dilution method to  obtain minimum inhibitory (MIC) and minimum bactericidal concentrations (MBC) of C. aurantifolia. Results: A total of 14 bacterial isolates were recovered from throat samples of 100 hospitalized patients with Staphylococcus aureus (43%, n=6) being  the most frequent while Escherichia coli (14.5%, n=2) was the least frequent. The isolates were generally resistant to penicillin, aminoglycoside and  fluoroquinolone groups of antibiotics tested. The zone of inhibition for hexane and methanol extracts of C. aurantifolia and aqueous extract of alum  on the bacterial isolates ranged from 11.5-19.2mm, 9.8-15.8mm, and 9.3-21.2mm respectively while those of selected antibiotics ranged from  7.0-25.0mm. The MICs of hexane and methanol extracts of C. aurantifolia against S. aureus were 10mg/ml and 25mg/ml, while the MBCs were 50  and 100mg/ml respectively. Conclusion: Findings from this study showed the presence of resistant pathogenic bacteria colonizing the throat of hospitalized patients receiving care at the Sobi Specialist Hospital, Ilorin, Nigeria. The crude extracts of C. aurantifolia and Alum in this study showed inhibitory effects (albeit at  higher concentrations) on the bacterial isolates comparable to the standard antibiotics. We posit that based on the inhibition capacity, further  studies to characterize, purify and isolate the active anti-bacterial components in the extracts should be considered for novelty.&nbsp

Extraction of lycopene with cell wall degrading enzymes from tomato (Lycopersicon esculentum Mill) fruits deteriorated by Aspergillus niger

Lycopene is the carotenoid which gives tomatoes and other red fruits their characteristic colour. It is one of the most powerful antioxidants and singlet oxygen quenching agents. It has been found to be of great medical importance with various anticancer effects and its ability to ameliorate several other medical conditions. Freshly ripe tomato fruits of the Roma vf variety and the Ibadan local variety were allowed to deteriorate after infection with a 96-hr-old culture of Aspergillus niger. Extraction of cell wall degrading enzymes produced during the deterioration process was carried out ten days after inoculation of the tomato fruits. The crude enzymes were precipitated using ammonium sulphate precipitation technique and employed in the extraction of lycopene from tomato peels. The yield of lycopene was 45.25mg/kg and 45.86mg/kg for enzymes extracted from the Roma vf and the Ibadan local varieties of tomato fruits respectively. This study established an improvement in lycopene extraction with crude preparation of cell wall degrading enzymes and compared the yield from the two enzymes obtained from the two most commonly available varieties of tomato fruits in Nigerian markets