521 research outputs found

    Development and characterization of MCF7 mammary carcinoma xenografts in a non-immunocompromised rat model

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    Purpose: To investigate the development of mammary tumours in female Sprague-dawley rats through a simple subcutaneous injection of human adenocarcinoma breast cells (MCF7) in combination with basement membrane matrix (BME).Methods: Nine Sprague-Dawley rats were divided into three groups. Group A received no injection, group B was injected with MCF7 cells at a cell density of 7.2 x 106/ml, and group C was co-injected with MCF7 and BME at 7.2 x 106/ml and 3.158 mg/ml, respectively. Tumour growth was observed over a duration of 70 days. Hematological analysis was performed using differential blood cell counts. Histological evaluation was carried out using standard LM techniques and H&E staining.Results: At day 35, RBC concentration across all groups was 8.10 x 106/mm3, whereas by day 70 the range decreased to (7.64 – 7.87) x 106/mm3. White blood cells (WBCs) were within normal range up to day 35, but monocytes and lymphocytes displayed an increase in concentration for group C. Mammary tissues from the thoracic region showed evidence of MCF7 cellular proliferation in both groups B and C.Conclusion: This study reveals that BME enhances tumour growth. Further studies are required to investigate optimization strategies for the development of mammary tumours in alternative recipient animal.Keywords: Tumour induction, MCF7, Histopathology, Thoracic mammary gland, Mammary tumour, Basement membrane matri

    Discrete approximations to vector spin models

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    We strengthen a result of two of us on the existence of effective interactions for discretised continuous-spin models. We also point out that such an interaction cannot exist at very low temperatures. Moreover, we compare two ways of discretising continuous-spin models, and show that, except for very low temperatures, they behave similarly in two dimensions. We also discuss some possibilities in higher dimensions.Comment: 12 page

    Investigation of Cucumeropsis mannii N. seed oil as potential biodiesel feedstock

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    Biodiesels fuels are being explored worldwide as alternatives for fossil fuels. The seeds of “Werewere” (Cucumeropsis mannii N., Cucurbitaceae) a fruit vegetable plant in Ghana with high oil content were analysed for their fatty acid composition as well as fuel properties to ascertain their potential as biodiesel fuel. The seeds contained 37.15% oil. The extracted seed oil by GC/MS analysis consisted of mainly linoleic acid (18:2) accounting for 58.8% of the total fatty acids. Other fatty acids detected were oleic acid (C18:1), stearic acid (C18:0) and palmitic acid (C16:0,) with contribution of 15.5, 14.1 and 11.5% respectively. Among the fuel properties measured were density (889.9 kg/m3), cetane number (57), flash point (155oC) and pour point (-3oC). The measured fuel properties of the fatty acid methyl ester of the oil were comparable to both the ASTMD 6751 and the EN 14214 biodiesel standards. Fuel properties were essentially identical with those of soybean, safflower, sunflower and “egusi” biodiesel. The Kinematic viscosity was however measured to be 15. mm2/s a value higher than most biodiesel fuels reported in the literature.Keywords: Renewable energy, biodiesel, vegetable oil, transesterification, fatty acid methyl ester

    Monte Carlo Simulations of Nuclear Fuel Burnup

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    In the operation of a nuclear power plant, it is very important to determine the time evolution of material composition and radionuclide inventory during the entire operation of the plant. In the experiments, the Monte Carlo N-Particle eXtended (MCNPX) code was found to be accurate in predicting the uranium fuel depletion, the plutonium production and the buildup of most of the fission products in a nuclear reactor. The goal in this chapter is to analyze the effect of different nuclear fuel grades on the total radioactivity of the reactor core by employing nuclear burnup calculations for the three different fuels: mixed oxide fuel (MOX), uranium oxide fuel (UOX) and commercially enriched uranium (CEU), utilizing simulations with MCNPX code. The calculated results indicate that there is a buildup of plutonium isotopes for UOX and CEU, whereas there is a decline in the plutonium radioisotopes for MOX fuel with burnup time. The study of reactor neutronic parameters showed UOX fuel performs better relative to MOX and CEU. Zircaloy, with low thermal neutron absorption cross-section and high thermal conductivity, produced better results for the effective multiplication factor Keff and hence proved to be a much more effective clad material

    Mechanism(s) Underlying Interactions Between Cattle Manure and Mineral Fertilizer in a Maize Field Soil in Ghana

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    A 70-day laboratory incubation study was conducted to unravel the mechanism(s) underlying synergistic interactions between organic and inorganic nutrient inputs to the soil. Soil from a maize farmer's field at Kpongu in the Upper West Region of Ghana was amended with a factorial combination of 0, 50% and 100% levels of the recommended rates (RR) of inorganic fertilizer and cattle manure and incubated at room temperature in plastic cups. Deionized water was added to maintain soil moisture at 70% field capacity throughout the incubation period. Cups were covered with gas-permeable parafilm. Soil sampling was done at 7, 28, 42, 56 and 70 days after incubation. The soil was analyzed for available phosphorus, organic carbon, microbial biomass carbon, nitrates, ammonium, soil urease activity, iron, and copper at each sampling. The addition of 100% RR NPK + 50% RR manure often results in higher amounts of the measured parameters,synergistic interactions and supply of nutrients to the soil, with longer residual effects. While all the under-studied mechanisms (improved nutrient synchrony, priming effects, general fertility improvement fertility) contribute to synergistic interactions, the improved nutrient synchrony mechanism is the most prominent. Farmers can therefore manage the timing of the nutrient inputs well to capitalize on this mechanism for improved soil fertility.&nbsp

    Insecticidal activities and chemical composition of the essential oil from Tarchonanthus camphoratus (L.), leaves against Sitophilus zeamais Motschulsky, and Sitophilus oryzae (L.)

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    The essential oil of Tarchonanthus camphoratus dry leaves growing in Kwa-Zulu Natal, South Africa was obtained by hydrodistillation and evaluated for its repellent effect, contact and fumigation toxicity against both Sitophilus zeamais and Sarocladium oryzae. Chemical composition of the essential oil was analysed by gas chromatography mass spectrometry (GC/MS). The study revealed that the essential oil of T. camphoratus had no contact and fumigation toxicity against stored insect pests, S. zeamais and S. oryzae. The oil, however, showed good repellent activity of over 50% after 24 h for all the concentrations used on both S. zeamais and S. oryzae. A total of 27 compounds accounting for 73% of the total oil composition were identified of which sesquiterpene hydrocarbons, (59.18%), were the most dominant. These results suggest that the essential oil of T. camphoratus could be considered a potential control agent of stored grain pests as a repellent

    The bacteria profiles of wounds in diabetic patients hospitalized in northern Kwazulu-Natal, South Africa

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    Diabetic wound infections still remain a health concern such that correct identification of bacteria is essential in monitoring the spread of the infections as well as in the administration of the correct treatment. This study therefore focuses on isolating and identifying bacteria present in diabetic wounds of hospitalized patients in northern KwaZulu-Natal and assessing their distribution.The wound specimen were collected and swabbed onto selective and differential media. The bacteria identities were presumptively ascertained through biochemical characterization (Gram-stain, catalase test, oxidase test and API) and then confirmed through 16S rDNA sequencing.A total of 42 isolates were recovered from 83% of the patients sampled from the three participating hospitals (X, Y, and Z). Gram-negative bacilli from Enterobacteriaceaewere predominant followed by Staphylococci spp and Enterococcus faecaliswith 43% polymicrobial cases from hospital Z and 29% from hospital X. Distribution of some opportunistic pathogens and nosocomially-acquired pathogens were also observed across the patients with five bacterial identities distributed among hospital X and Z. The adverse effects associated with the recovered bacteria in diabetic wounds pose a serious health concern and preventive measure should be taken.Keywords: Diabetes mellitus, wounds, bacteria, infectio

    Early contractor involvement in government construction projects in Ghana

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    The importance of Early Contractor Involvement (ECI) and the input in project development has been acknowledged, however little has been done in practice to actually involve contractors early in government projects in Ghana. This study explores the prospects of early contractor involvement in public construction projects in Ghana. It investigates current construction procurement practices, evaluates potential benefits and challenges of ECI and examines the prospects of adopting the practice in public construction procurement. The research adopted quantitative research methodology using survey that solicited the opinions of 100 professionals from contracting organisations, consulting firms and the relevant government ministry. Results from the study shows that some challenges encountered under the traditional procurement route are linked to poor project development. It also reveals that the government of Ghana might be reluctant to try ECI on its projects however, if adopted; the practice could be successfully implemented and perpetuated. The research shows that ECI could be greatly beneficial to public sector projects if the government embraces the concept and explore the numerous benefits that could be achieved; the practice has good prospects in the delivery of public sector construction projects in Ghana

    Anti-oxidant, anti-inflammatory and antiacetylcholinesterase activity of betulinic acid and 3β- acetoxybetulinic acid from Melaleuca bracteata ‘Revolution Gold’

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    Purpose: To evaluate the anti-oxidant, anti-inflammatory and anti-acetylcholine esterase activities of betulinic acid (BA) and 3β- acetoxybetulinic acid (BAA) from Melaleuca bracteata. ‘Revolution Gold’.Methods: Betulinic acid was isolated from the ethyl acetate extract of M. braceteata while BAA was synthesized by acetylation of BA. Structural elucidation of the compounds was achieved by spectroscopic methods. Antioxidant potential was determined using superoxide dismustase (SOD) and catalase assay kits while iron chelation activity assessed with ferrozin. Anti-inflammatory activity was determined using cotton pellet-induced granuloma rat model. Cyclooxygenase (COX) activity evaluated by COX kits; acetylcholine kit was used for anti-acetylcholinesterase (ACHE) study.Results: The compounds significantly (p < 0.05) dose-dependently inhibited ACHE and inflammatory activity. They also significantly decreased the inhibition of SOD, catalase activity but increased iron chelation activities in a dose-dependent manner. However, BAA showed higher activity than BA for all the parameters. BAA also had a greater inhibitory effect on COX-2 than on COX-1. BAA (IC50, 0.88 mg/mL) showed better iron chelation than citric acid (0.96 ± 0.04) and EDTA (1.04 ± 0.03), the positive control.Conclusion: BA and BAA possess anti-ACHE, anti-inflammatory, antioxidant and anti-COX activities. Structural modification of BAA influences its biological activities. Therefore, BAA can potentially serve as a scaffold in synthesizing potent neurodegeneration drugs.Keywords: Betulinic acid, 3β-Acetoxybetulinic acid, Antioxidant, Anti-inflammatory, Antiacetylcholinesterase, Melaleuca bracteata. ‘Revolution Gold
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