Proximate composition and basic phytochemical assessment of two common varieties of Terminalia catappa (Indian Almond).

Terminalia catappa is a common tree found in Ghana but it is much underutilized. The objective was therefore set to investigate the medicinal and nutritive potential of two common varieties of the plant; the red and yellow varieties. The proximate composition of the nut and pulp of the two varieties were determined using certified methods of the Association of Official Analytical Chemists. Phytochemical screening was also determined using standard screening methods. The red nut had a moisture content of 31.05%; crude fat, 36.9%; protein, 22.19%; ash, 2.76%; carbohydrate, 5.24% and crude fibre, 1.86%. The pulp contained up to 81.96% moisture; 0.04% crude fat; 1.07% protein; 1.47% ash; 14.05% carbohydrates and 1.41% crude fibre. The moisture content constituted 32.06% of the nut of the yellow variety, crude fat was 35.69%; protein, 23.05%; ash, 2.68%; carbohydrate, 4.92% and crude fibre, 1.6%. The pulp of the yellow variety had the proximate composition as: moisture, 84.37%; crude fat, 0.05%; crude protein, 1.54%; ash, 1.62%; carbohydrate, 11.03%; crude fibre, 1.39%. The pulps of both varieties were found to contain saponins, general glycosides, flavonoids, alkaloids, anthraquinones and anthraquinone glycosides. The nut of the yellow variety had terpenoids and steroids present in it while the nut of the red variety had alkaloids present. Statistical analyses carried out showed that there were no significant differences (p≤0.05) between the two varieties based on their proximate composition

Carbon Footprint of the Large Scale Gold Mining Industry of Ghana

Mining has been an important economic activity accounting for a substantial part of foreign exchange and government revenue. The gold mining sector has undergone considerable expansion due to liberalization with more foreign mining companies investing in the sector in particular large-scale open pit gold mining. Resultant expansion in mining has led to heightened environmental concerns and significant challenges due to key activities used in the mining operations hence contributing to greenhouse gas emissions. Investigations were conducted to assess the sources and key activities in large scale gold open pit mining operations in Ghana giving rise to greenhouse gas generation. The study adopted the Intergovernmental Panel on Climate Change (IPCC) guideline for estimating greenhouse gas inventory. The operational boundary as against the organizational boundary was considered for the study. The operational boundary was drawn around the physical mining site. Within this boundary, the emissions were quantified and reported under direct emission due to company activities (Scope 1) and indirect emissions from secondary use or activity (Scope 2). The study found that activities due to land use, blasting, fuel use to power mobile equipment and stationary combustion sources, electricity use and waste management were the contributing greenhouse gas emission sources in a large scale gold mining operation with electricity use and fuel used in transportation accounting for 92.46% of the total emissions. Average contribution of the large scale gold mining industry in Ghana to the total national greenhouse gas emission inventory for the country was established to be 11.08%

Evaluating the Effect of Shear Stress on Graft-To Zwitterionic Polycarboxybetaine Coating Stability Using a Flow Cell

The effect of surface coatings on the performance of antifouling activity under flow can be influenced by the flow/coating interactions. This study evaluates the effect of surface coatings on antifouling activity under different flows for the analyses of coating stability. This was done by exposing DOPA-PCB-300/dopamine coated polydimethylsiloxane (PDMS) to physiological shear stresses using a recirculation system which consisted of dual chamber acrylic flow cells, tygon tubing, flow probe and meter, and perfusion pumps. The effect of shear stress induced by phosphate buffered saline flow on coating stability was characterized with differences in fibrinogen adsorption between control (coated PDMS not loaded with shear stress) and coated samples loaded with various shear stresses. Fibrinogen adsorption data showed that relative adsorption on coated PDMS that were not exposed to shear (5.73% ± 1.97%) was significantly lower than uncoated PDMS (100%, p \u3c 0.001). Furthermore, this fouling level, although lower, was not significantly different from coated PDMS membranes that were exposed to 1 dyn/cm2 (9.55% ± 0.09%, p = 0.23), 6 dyn/cm2 (15.92% ± 10.88%, p = 0.14), and 10 dyn/cm2 (21.62% ± 13.68%, p = 0.08). Our results show that DOPA-PCB-300/dopamine coatings are stable, with minimal erosion, under shear stresses tested. The techniques from this fundamental study may be used to determine the limits of stability of coatings in long-term experiments

Variation in Stability of Endogenous Reference Genes in Fallopian Tubes and Endometrium from Healthy and Ectopic Pregnant Women

RT-qPCR is commonly employed in gene expression studies in ectopic pregnancy. Most use RN18S1, β-actin or GAPDH as internal controls without validation of their suitability as reference genes. A systematic study of the suitability of endogenous reference genes for gene expression studies in ectopic pregnancy is lacking. The aims of this study were therefore to evaluate the stability of 12 reference genes and suggest those that are stable for use as internal control genes in fallopian tubes and endometrium from ectopic pregnancy and healthy non-pregnant controls. Analysis of the results showed that the genes consistently ranked in the top six by geNorm and NormFinder algorithms, were UBC, GAPDH, CYC1 and EIF4A2 (fallopian tubes) and UBC and ATP5B (endometrium). mRNA expression of NAPE-PLD as a test gene of interest varied between the groups depending on which of the 12 reference genes was used as internal controls. This study demonstrates that arbitrary selection of reference genes for normalisation in RT-qPCR studies in ectopic pregnancy without validation, risk producing inaccurate data and should therefore be discouraged

Hemocompatibility Comparison of Biomedical Grade Polymers Using Rabbit Thrombogenicity Model for Preparing Nonthrombogenic Nitric Oxide Releasing Surfaces

Nitric oxide (NO) is an endogenous vasodilator as well as natural inhibitor of platelet adhesion/ activation. Nitric oxide releasing (NOrel) materials can be prepared by doping an NO donor species, such as diazeniumdiolated dibutylhexanediamine (DBHD/N2O2), within a polymer coating. The inherent hemocompatibility properties of the base polymer can also influence the efficiency of such NO release coatings. In this study, four biomedical grade polymers were evaluated in a 4 h rabbit model of thrombogenicity for their effects on extracorporeal circuit thrombus formation and circulating platelet count. At the end of 4 h, Elast-Eon E2As was found to preserve 58% of baseline platelets versus 48, 40, and 47% for PVC/DOS, Tecophilic SP-60D-60, and Tecoflex SG80A, respectively. Elast-Eon also had significantly lower clot area of 5.2 cm2 compared to 6.7, 6.1, and 6.9 cm2 for PVC/DOS, SP-60D-60, and SG80A, respectively. Based on the results obtained for the base polymer comparison study, DBHD/N2O2-doped E2As was evaluated in short-term (4 h) rabbit studies to observe the NO effects on prevention of clotting and preservation of platelet function. Platelet preservation for this optimal NO release formulation was 97% of baseline after 4 h, and clot area was 0.9 cm2 compared to 5.2 cm2 for controls, demonstrating that combining E2As with NO release provides a truly advanced hemocompatible polymer coating for extracorporeal circuits and potentially other blood contacting applications

Engineering Characterisation of Aggregates from Some Selected Areas in Kumasi, Ghana

The increase in engineering projects translates to an increase in demand for construction materials, for example, aggregates which are a major component in concrete works. There are many quarries in the Kumasi area which produce aggregates for use in construction works. However, there is no readily available information on the geological and geotechnical properties of these aggregates for use by engineers during the planning, design and construction of projects. This project therefore sought to characterise the aggregate from selected areas (close to some major quarries) in Kumasi based on their geological and engineering properties for construction purposes. Results of the study indicate that Aggregates from sampling locations KP and CS passed the FI test with those from CS being the only ones to pass for EI, making them the best aggregates in terms of Flakiness and Elongation Indices. The aggregates from all the sampling locations passed for the Specific Gravity and Water Absorption tests with CS aggregates giving the best results indicating high strength and good rate of water absorption. Aggregate from sampling location NM gave the best result for the Aggregate Impact Value test indicating high resistance to sudden impacts and shocks. With the Ten Percent Fines Value and the Aggregate Crushing Value Tests, CS yet again produced the aggregates with the best results. The aggregate gave a very high result even under the wet/soaked condition when all the others were giving very low results. Aggregates from this sampling locations can withstand loading gradual compression better than the rest. Finally, the KP aggregates gave the best results for the Los Angeles Abrasion Value which suggests such materials to be the hardest and toughest to resist crushing, degradation and disintegration. Aggregates from the CS, however gave the second best results. From the study, it was concluded that the most suitable location to obtain good quality aggregates is around CS as its aggregates gave the best results in almost all the tests

In Vitro and in Vivo Study of Sustained Nitric Oxide Release Coating Using Diazeniumdiolate-doped Poly(vinyl chloride) Matrix with Poly(lactide-co-glycolide) Additive

Nitric oxide (NO) is an endogenous vasodilator as well as natural inhibitor of platelet adhesion and activation that can be released from a NO donor species, such as diazeniumdiolated dibutylhexanediamine (DBHD/N2O2) within a polymer coating. In this study, various Food and Drug Administration approved poly(lactic-co-glycolic acid) (PLGA) species were evaluated as additives to promote a prolonged NO release from DBHD/N2O2 within a plasticized poly(vinyl chloride) (PVC) matrix. When using an ester-capped PLGA additive with a slow hydrolysis time, the resulting coatings continuously release between 7 and 18 × 10−10 mol cm−2 min−1 NO for 14 days at 37 °C in PBS buffer. The corresponding pH changes within the polymer films were visualized using pH sensitive indicators and are shown to correlate with the extended NO release pattern. The optimal combined diazeniumdiolate/PLGA-doped NO release (NOrel) PVC coating was evaluated in vitro and its effect on the hemodynamics was also studied within a 4 h in vivo extracorporeal circulation (ECC) rabbit model of thrombogenicity. Four out of 7 control circuits clotted within 3 h, whereas all the NOrel coated circuits were patent after 4 h. Platelet counts on the NOrel ECC were preserved (79 ± 11% compared to 54 ± 6% controls). The NOrel coatings showed a significant decrease in the thrombus area as compared to the controls. Results suggest that by using ester-capped PLGAs as additives to a conventional plasticized PVC material containing lipophilic diazeniumdiolates, the NO release can be prolonged for up to 2 weeks by controlling the pH within the organic phase of the coating

The Hemocompatibility of a Nitric Oxide Generating Polymer that Catalyzes S-nitrosothiol Decomposition in an Extracorporeal Circulation Model

Nitric oxide (NO) generating (NOGen) materials have been shown previously to create localized increases in NO concentration by the catalytic decomposition of blood S-nitrosothiols (RSNO) via copper (Cu)-containing polymer coatings and may improve extracorporeal circulation (ECC) hemocompatibility. In this work, a NOGen polymeric coating composed of a Cuo-nanoparticle (80 nm)-containing hydrophilic polyurethane (SP-60D-60) combined with the intravenous infusion of an RSNO, S- nitroso-N-acetylpenicillamine (SNAP), is evaluated in a 4 h rabbit thrombogenicity model and the anti-thrombotic mechanism is investigated. Polymer films containing 10 wt.% Cuo-nanoparticles coated on the inner walls of ECC circuits are employed concomitantly with systemic SNAP administration (0.1182 μmol/kg/min) to yield significantly reduced ECC thrombus formation compared to polymer control + systemic SNAP or 10 wt.% Cu NOGen + systemic saline after 4 h blood exposure (0.4 ± 0.2 NOGen/SNAP vs 4.9 ± 0.5 control/SNAP or 3.2 ± 0.2 pixels/cm2 NOGen/saline). Platelet count (3.9 ± 0.7 NOGen/SNAP vs 1.8 ± 0.1 control/SNAP or 3.0 ± 0.2 × 108/ml NOGen/saline) and plasma fibrinogen levels were preserved after 4 h blood exposure with the NOGen/SNAP combination vs either the control/SNAP or the NOGen/saline groups. Platelet function as measured by aggregometry (51 ± 9 NOGen/SNAP vs 49 ± 3% NOGen/saline) significantly decreased in both the NOGen/SNAP and NOGen/saline groups while platelet P-selectin mean fluorescence intensity (MFI) as measured by flow cytometry was not decreased after 4 h on ECC to ex vivo collagen stimulation (26 ± 2 NOGen/SNAP vs 29 ± 1 MFI baseline). Western blotting showed that fibrinogen activation as assessed by Aγ dimer expression was reduced after 4 h on ECC with NOGen/SNAP (68 ± 7 vs 83 ± 3% control/SNAP). These results suggest that the NOGen polymer coating combined with SNAP infusion preserves platelets in blood exposure to ECCs by attenuating activated fibrinogen and preventing platelet aggregation. These NO-mediated platelet changes were shown to improve thromboresistance of the NOGen polymer-coated ECCs when adequate levels of RSNOs are present

Thermomechanical Characterization of Carbon Black Reinforced Rubbers During Rapid Adiabatic Straining

The thermo-mechanical properties of carbon black reinforced natural and styrene butadiene rubbers are investigated under rapid adiabatic conditions. Eleven carbon black grades with varying surface area and structure properties at 40 parts per hundred (phr) loading are studied and the unreinforced equivalents are included for reference. The results show a strong correlation of the modulus, mechanical hysteresis, temperature rise and calculated crystallinity of the rubbers measured in tensile extension with strain amplification factors. This highlights the influence of matrix overstraining on microstructural deformations of the rubber upon extension. The strain amplification factors are calculated via the Guth-Gold equation directly from carbon black type and loading, allowing a correlation of the fundamental morphological properties of carbon black with thermal and mechanical properties of rubbers upon extension. Analysis of the thermal measurements of the rubber compounds upon extension and retraction and contrasting between crystallizing and non-crystallizing rubbers reveals that a substantial irreversible heat generation is present upon extension of the rubber compounds. These irreversible effects most likely originate from microstructural damage mechanisms which have been proposed to account for the Mullins Effect in particle reinforced rubbers