Carbothermic reduction kinetics of Ka’oje (Nigeria) manganese ore

The kinetics of carbothermic reduction of manganese ore from Ka’oje deposit has been established. X-Ray diffraction analysis of the as-mined ore samples affirmed the presence of pyrolusite as the major manganese mineral in the ore, existing alongside with iron mineral present as hematite optically identified by transmitted infrared light microscopy. Samples with particles size ranges—106 μm were isothermally treated using charcoal of 52.17% carbon content as the reductant. The treatment was carried out at 550˚C, 600˚C, 650˚C and 750˚C with varied roasting retention time. Ore-mineral reduction kinetic model equations were developed using the generated thermal data. Results showed that the apparent activation energy (Ea) of the chemical reaction controlled reduction was 19.99 KJ/mole using the diminishing area rate equation. Obtained Ea values for diffusion controlled reduction of the ore-minerals were 36.28 Kj/mole and 29.56 KJ/mole using Jander and Ginsthing-Brounshtein equations respectively. These hereby established reduction susceptibility of the manganese oxide mineral from higher oxide to lower oxides meant for further hydrometallurgical treatments

Evaluation of Sheanut Shell-Reinforced Automotive Brake Pad

For over a century now, asbestos has been used as friction material in the manufacture of brake pads but its use is currently been avoided due to its carcinogenic nature and potential to cause cancer. This study is focused on development of a new brake pad using sheanut shell (SNS) which is an eco-friendly material as the reinforcement and epoxy resin as the binder. Other constituents used are calcium carbonate (CaCO3), graphite and aluminium oxide (Al2O3). Five compositions were formulated with the epoxy resin and reinforcement varied at interval of 5 wt% while CaCO3, graphite and Al2O3 remain constant at 30, 10 and 10 wt% respectively. The developed brake pads were subjected to compressive, abrasive and water absorption tests while their densities were also measured. The results showed that the compressive strength, abrasive strength and the density of the samples decreased as the reinforcement content increased while the water absorption rate increased as the reinforcement content increased. The value of the compressive strength ranged from 64.88 – 93.04Mpa, wear rate from 3.13 – 6.25mg/m, water absorption from 0.899 – 2.722% and density from 0.764 – 1.487g/m3. The result of this research indicates that SNS particles can be used as a replacement for asbestos in brake pad production

MODIFICATION OF NIGERIAN BENTONITE FOR UTILIZATION IN OIL WELL DRILLING OPERATIONS

More than 80 bentonite clay deposit sites had been identified in Nigeria. Yet, almost all clay and additives used for drilling oil well are imported. The reason is partly that in their natural states, they do not swell while polymers in their raw forms remain unstable at high temperatures. This study aimed at evaluating the potentials of chemically modified Nigerian bentonite for application in the oil and gas industry. The Gombe bentonite from Gombe State was beneficiated using NAHCO3 and slurries were made by dispersion in distilled water. In the presence of other local additives, evaluation of the slurries was carried out on the basis of filtration loss and rheology at different temperatures (30, 60 and 85 oC) using a Central Composite Design (CCD). The clay sample was characterized for mineral and elemental compositions using X-ray diffractometer (XRD) and X-ray fractometer (XRF) while proximate analysis was carried out on the additives. At the optimum condition, the result shows a significant improvement in mud rheology and fluid loss at various temperatures which are in close agreement with the API recommended standard

Folate transport by prawn hepatopancreas brush-border membrane vesicles.

The transport system of folic acid (Pte-Glu) b y brush-borde r membrane vesicles (BBMV ) isolated from prawn (Penaeus japonicm) hepatopancreas , was studied by measuring the uptake of Pte-Glu . This uptake was found to have two components , intravesicular transport and membrane binding . Membrane binding was not affected by the presence of a trans - membrane pH-gradient at a short incubation period . However , a transmembrane pH - gradient increased membrane binding at 6 0 min. The transpor to f Pte-Glu appeared to be carrier-mediated , was stimulated by an inwardly proton gradient (p H 5. 5 outside , 7. 4 inside ) and was unaffected by a sodium-gradient . The relationship between pH gradient-driven Pte-Glu uptake and medium Pte-Glu concentration followed saturating Michaelis-Menten kinetics . Eadie-Hofste e representation of the pH gradient-driven Pte-Glu uptake indicated a single transport system with a Km of 0.3 7 ^ Man d Vmax of 1.06pmol/mg protein/15s . These findings indicate that BBM V isolated from prawn hepatopancreas possesses a Pte - Glu transport system similar to that described in mammalian intestine

Chemotherapeutic agent 5-fluorouracil increases survival of SOD1 mouse model of ALS

Amyotrophic lateral sclerosis (ALS) is a lethal motor neuron disease with no cure. Currently there are only two ALS drugs approved by the FDA, both with a limited therapeutic effect. In the search for drug candidates for ALS, we studied the effect of known stem cell mobilizing agents (treatment) and antimetabolite 5-fluorouracil (5-FU) (anti-treatment) in SOD1G93A model of ALS. Surprisingly, we found that anti-cancer drug 5-FU increases lifespan, delays the disease onset and improves motor performance in ALS mice. Although we were not able to demonstrate the mechanistic basis of the beneficial 5-FU action in ALS mice, our findings suggest that 5-FU or similar drugs are possible drug candidates for the treatment of motor neuron diseases through drug repurposing

Cloning of Salmonella enterica serovar Enteritidis fimbrial protein SefA as a surface protein in Escherichia coli confers the ability to attach to eukaryotic cell lines

The gene for the Salmonella enterica serovar Enteritidis fimbrial protein SefA was cloned into an Escherichia coli surface expression vector and confirmed by Western blot assay. E. coli clones expressing SefA attached to avian ovary granulosa cells and HEp-2 cells, providing evidence for the involvement of SefA in the ability of Salmonella to attach to eukaryotic cells.Peer reviewedAnimal Scienc

CSF1R blockade slows the progression of amyotrophic lateral sclerosis by reducing microgliosis and invasion of macrophages into peripheral nerves

Inflammation is a common neuropathological feature in several neurological disorders, including amyotrophic lateral sclerosis (ALS). We have studied the contribution of CSF1R signalling to inflammation in ALS, as a pathway previously reported to control the expansion and activation of microglial cells. We found that microglial cell proliferation in the spinal cord of SOD1G93A transgenic mice correlates with the expression of CSF1R and its ligand CSF1. Administration of GW2580, a selective CSF1R inhibitor, reduced microglial cell proliferation in SOD1G93A mice, indicating the importance of CSF1-CSF1R signalling in microgliosis in ALS. Moreover, GW2580 treatment slowed disease progression, attenuated motoneuron cell death and extended survival of SOD1G93A mice. Electrophysiological assessment revealed that GW2580 treatment protected skeletal muscle from denervation prior to its effects on microglial cells. We found that macrophages invaded the peripheral nerve of ALS mice before CSF1R-induced microgliosis occurred. Interestingly, treatment with GW2580 attenuated the influx of macrophages into the nerve, which was partly caused by the monocytopenia induced by CSF1R inhibition. Overall, our findings provide evidence that CSF1R signalling regulates inflammation in the central and peripheral nervous system in ALS, supporting therapeutic targeting of CSF1R in this disease

Pharmacological effects of mitraphylline from Uncaria tomentosa in primary human monocytes: Skew toward M2 macrophages

© 2015 Elsevier Ireland Ltd. All rights reserved. Ethnopharmacological relevance Uncaria tomentosa (Willdenow ex Roemer & Schultes) DC. (Rubiaceae) is a Peruvian thorny liana, commonly known as >cat's claw>, and traditionally used in folk medicine to deal with several inflammatory diseases. Mitraphylline (MTP) is the most abundant pentacyclic oxindolic alkaloid (POA) from U. Tomentosa and has been reported to modify the inflammatory response. Herein, we have sought to identify the mechanisms underlying this modulatory effect of MTP on primary human monocytes and its ability to regulate differentiation processes on human primary monocyte and monocyte-derived macrophages. Material and methods In vitro studies with human primary monocytes and monocyte-derived macrophages were performed. Monocytes and M0 macrophages were exposed to MTP (25 μM) and LPS (100 ng/mL). M0 macrophages were polarized to M1 and M2 phenotypes in the absence or presence of MTP. The activation state of monocytes/macrophages was assessed by flow cytometry, gene expression and protein analysis of different specific markers. Results In human primary monocytes, the incubation of MTP for 24 h reduced the number of classical (CD14++CD16-) and intermediate (CD14++CD16+) subsets when compared to untreated or LPS-treated cells. MTP also reduced the chemotactic capacity of human primary monocytes. In addition, MTP promoted the polarization of M0 macrophages toward an anti-inflammatory M2 phenotype, the abrogation of the release of pro-inflammatory cytokines such as TNFα, IL-6 or IL-1β, as well as the restoration of markers for M2 macrophages in LPS-treated M1 macrophages. Conclusions Our results suggest that MTP may be a key modulator for regulating the plasticity of monocytes/macrophages and the attenuation of the inflammatory response.This work was supported by the University of Seville, “V Own Research Plan” contract to BB and QA. MS has the benefit of a FPI fellowship (BES-2012–056104) of MICINN.Peer Reviewe