100 research outputs found

    Optimization of Transesterification Parameters of Biodiesel Produced from Sword Bean (Cavalia gladiate) Seed Oil

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    The subject of this study was to optimize the transesterification parameters of biodiesel produced from sword bean (C. gladiate) using Response Surface Methodology (RSM). Four transesterification parameters (Reaction temperature 55 0C, Catalyst concentration 0.4 wt%, Methanol to oil ratio 4:1 and reaction time 60 min) were optimized. Data obtained revealed that the optimum reaction conditions for the transesterification of C. gladiata seed oil resulted in 92.88% biodiesel yield. Multiple regression analysis produced a quadratic polynomial equation for methylester and a linear relationship was recorded between the observed and predicted value (R2 = 0.9647) with a significant molar ratio and temperature.  The interaction terms of methanol to oil, molar ratio and temperature with reaction time exhibited a positive effect on the methylester yield. The response surface methodology was found to be a suitable technique for optimizing transesterification process and producing biodiesel that meets the ASTM standard

    Assessment of Selected Heavy Metal Content on Dumpsites Soil and Vegetables Grown in Muwo Metropolis, Niger State, Nigeria

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    This study examines the concentration of heavy metals in soil samples and some vegetables (spinach, water leaf, bitter leaf and jute mallow) cultivated around dumpsites in Muwo Metropolis, Niger State, Nigeria. The soil samples and vegetable were analyzed for Ni, Zn, Cu, Pb and Cd using AA500 spectrophotometer after acid digestion. Data obtained show that, the Pb (1.684 mg/kg of Jute) content was high compared to other metals study in this work. Concentration of Zn was 1.993, 0.862 and 0.443 mg/kg for water leaf, soil and control sample respectively. The content of Pb was 1.727, 1.738 and ND mg/kg for water leaf, soil and control sample respectively. Also, the concentration of Pb was 1.736, ND and 0.457 mg/kg for spinach, soil and control sample respectively. However, the content of Zn was 0.786, 0.751 and 0.554 mg/kg for spinach, soil and control sample respectively The accumulation of heavy metals in agricultural soils is of increasing concern because of, potential health risks, food safety as well as its detrimental effects on the soil ecosystem and human health. The pollution indexes of Ni contents are 0.439, 0.378, and 0.083 for jute, soil and control sample respectively. While Zn concentration was 1.117, 0.858 and 0.492 for jute, soil and control sample respectively. The result of this study shows that Pb concentrations are present in high levels in the study area at the different level of contamination

    Advanced colorectal polyps with the molecular and morphological features of serrated polyps and adenomas: concept of a ‘fusion’ pathway to colorectal cancer

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    Jass J R, Baker K, Zlobec I, Higuchi T, Barker M, Buchanan D & Young J (2006) Histopathology 49, 121–131 Advanced colorectal polyps with the molecular and morphological features of serrated polyps and adenomas: concept of a ‘fusion’ pathway to colorectal cancer AIM: To establish and explain the pattern of molecular signatures across colorectal polyps. METHODS AND RESULTS: Thirty-two sessile serrated adenomas (SSA), 10 mixed polyps (MP), 15 traditional serrated adenomas (SA), 49 hyperplastic polyps (HP) and 84 adenomas were assessed for mutation of KRAS and BRAF and aberrant expression of p53. The findings were correlated with loss of expression of O-6-methylguanine DNA methyltransferase (MGMT). KRAS mutation occurred more frequently (26.5%) than BRAF mutation (4.8%) in adenomas (P < 0.001) and particularly in adenomas with villous architecture (50%). Loss of expression of MGMT correlated with KRAS mutation in small tubular adenomas (P < 0.04). BRAF mutation was frequent in HPs (67%) and SSAs (81%), while KRAS mutation was infrequent (4% and 3%, respectively). Of MPs and SAs, 72% had either BRAF or KRAS mutation. Aberrant expression of p53 was uncommon overall, but occurred more frequently in MPs and SAs (12%) than adenomas (1%) (P < 0.04) and there was concordant loss of expression of MGMT. CONCLUSIONS: Molecular alterations that are characteristic of the serrated pathway and adenoma–carcinoma sequence can co-occur in a minority of advanced colorectal polyps that then show morphological features of both pathways. These lesions account for only 2% of colorectal polyps, but may be relatively aggressive

    The modified 2VO ischemia protocol causes cognitive impairment similar to that induced by the standard method, but with a better survival rate

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    Permanent bilateral occlusion of the common carotid arteries (2VO) in the rat has been established as a valid experimental model to investigate the effects of chronic cerebral hypoperfusion on cognitive function and neurodegenerative processes. Our aim was to compare the cognitive and morphological outcomes following the standard 2VO procedure, in which there is concomitant artery ligation, with those of a modified protocol, with a 1-week interval between artery occlusions to avoid an abrupt reduction of cerebral blood flow, as assessed by animal performance in the water maze and damage extension to the hippocampus and striatum. Male Wistar rats (N = 47) aged 3 months were subjected to chronic hypoperfusion by permanent bilateral ligation of the common carotid arteries using either the standard or the modified protocol, with the right carotid being the first to be occluded. Three months after the surgical procedure, rat performance in the water maze was assessed to investigate long-term effects on spatial learning and memory and their brains were processed in order to estimate hippocampal volume and striatal area. Both groups of hypoperfused rats showed deficits in reference (F(8,172) = 7.0951, P < 0.00001) and working spatial memory [2nd (F(2,44) = 7.6884, P < 0.001), 3rd (F(2,44) = 21.481, P < 0.00001) and 4th trials (F(2,44) = 28.620, P < 0.0001)]; however, no evidence of tissue atrophy was found in the brain structures studied. Despite similar behavioral and morphological outcomes, the rats submitted to the modified protocol showed a significant increase in survival rate, during the 3 months of the experiment (P < 0.02)

    Detection and Characterization of Oncogene Mutations in Preneoplastic and Early Neoplastic Lesions

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    While it has been nearly 30 years since its discovery, the ras family of genes has not yet lost its impact on basic and clinical oncology. These genes remain central to the field of molecular oncology as tools for investigating carcinogenesis and oncogenic signaling, as powerful biomarkers for the identification of those who have or are at high risk of developing cancer, and as oncogene targets for the design and development of new chemotherapeutic drugs. Mutational activation of the K-RAS proto-oncogene is an early event in the development and progression of the colorectal, pancreatic, and lung cancers that are the major causes of cancer death in the world. The presence of point mutational "hot spots" at sites necessary for the activation of this proto-oncogene has led to the development of a number of highly sensitive PCR-based methods that are feasible for the early detection of K-RAS oncogene mutations in the clinical setting. In light of these facts, mutation at the K-RAS oncogene has the potential to serve as a useful biomarker in the early diagnosis and risk assessment of cancers with oncogenic ras signaling. This chapter describes a highly sensitive method for detecting mutant K-RAS, enriched PCR, and its application to early detection of alterations in this oncogene in preneoplastic and early neoplastic lesions of the colon and rectum
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