506 research outputs found

    Corrosion Protection of Al Alloys: Organic Coatings and Inhibitors

    Get PDF

    Microscopic, Physicochemical and Phytochemical Evaluation of Stem bark of Aubrevillea kerstingii (Harms) Pellegr. (Mimosaceae)

    Get PDF
    Microscopic, physicochemical and phytochemical evaluation gives detailed valuable information that is useful in determination of the identity, quality and purity of medicinal plants, crude drugs and herbal products. The research was carried out in order to determine the microscopic, physicochemical and phytochemical parameters of stem bark extract of Aubrevillea kerstingii. The macroscopic, microscopic, chemo-microscopic and physicochemical and preliminary phytochemical screening parameters were determined according to standard methods.The microscopic features revealed the presence of thin walled, radially arranged cork cells, well developed cortex, bundles of sclerenchymatous cells and numerous prismatic calcium oxalate crystals The chemo-microscopy of the powdered stem bark revealed the presence of some cell wall materials and cell inclusions. Physicochemical parameters determined in this study showed moisture content to be 8.2 ± 0.07, total ash value 9.23 ± 0.56, acid insoluble ash 1.49 ± 0.12, water soluble ash 5.52 ± 0.10, alcohol extractive value 26.50 ± 0.61 and water extractive value 33.4 ± 0.36. Preliminary phytochemical screening revealed the presence of saponins, triterpenes, flavonoids, tannins, alkaloids and carbohydrate. The parameters of stem bark of Aubrevillea kerstingii determined in this study will help in establishing the quality and purity of the plant. Keywords: Aubrevillea kerstingii, Fabaceae, Physicochemical, Phytochemica

    Neutron Flux Variation at the Inner Irradiation Channel of the Nigeria Research Reactor-1 (NIRR-1)

    Get PDF
    In order to ascertain the level of flux variation in one of the inner irradiation channels of the Nigeria Research Reactor-1 (NIRR-1), the irradiation container used for routine activation analysis was employed with copper wires as flux monitors. Measurements were carried out with these wires arranged in axial direction to determine the thermal neutron flux at selected positions using absolute foil activation method. Our results show that there exists a slight flux variation from one position to another ranging from (4.57 ± 0.24) x 1011 to (5.20 ± 0.20) x 1011 cm-2s-1. Individual foil shows slight flux variation from one position to another in the same irradiation container but they all pointed toward a level of stability in spite of the recent installation of the cadmium lined irradiation channel. The values obtained in this work are in good agreement with the previously measured value of (5.14 ± 0.24) x 1011 cm-2s-1 after commissioning of NIRR-1. This shows that the cadmium lined installation does not affect the flux stability. In order to improve the accuracy of neutron activation analysis (NAA) using NIRR-1 facility, there is need for flux corrections to be made by miniature neutron source reactor (MNSR) users during NAA particularly long irradiation, where more than six samples are irradiated simultaneously in the same container

    Artisanal Inland Water Fishing and Challenges of Livelihood Sustainability in Ibi Local Government Area, Taraba State Nigeria

    Get PDF
    This study examined challenges of livelihood sustainability from artisanal inland water fishing activities in Ibi LGA, Taraba State, Nigeria. Descriptive survey design was adopted. Purposive sampling was used in selecting 406 respondents from 12 communities in 6 political wards of the LGA. Descriptive statistics was used to analyse 401 questionnaires retrieved. Findings of the study reveal decline in daily fish catch from three baskets 10 years ago to only one basket presently. Also, income from fishing has declined from ₦150,000 (192)monthly10yearsagotolessthan50,000(192) monthly 10 years ago to less than ₦50,000 (64) presently. Factors responsible for decline in fish catch include rising water level, temperature increase, pollution, climate change, seasonality and unsustainable fishing practices. The unsustainable fishing practices include use of chemicals, small size nets and mosquito nets in fishing. The results reveal that fishermen engaged in non-fishing activities, fish farming and construction of fishing ponds along the floodplain as a way of achieving livelihood sustainability. Challenges of livelihood sustainability include seasonality of fishing activities, decline in fish stocks, use of traditional fishing methods and unsustainable fishing practices among others. The study recommend the need to enforce extant laws on fishery protection,  enlightenment campaign, and government support to fishing cooperatives

    Sodium Stibogluconate (SSG) & Paromomycin Combination Compared to SSG for Visceral Leishmaniasis in East Africa: A Randomised Controlled Trial

    Get PDF
    Visceral leishmaniasis (VL) is a parasitic disease with about 500,000 new cases each year and is fatal if untreated. The current standard therapy involves long courses, has toxicity and there is evidence of increasing resistance. New and better treatment options are urgently needed. Recently, the antibiotic paromomycin (PM) was tested and registered in India to treat this disease, but the same dose of PM monotherapy evaluated and registered in India was not efficacious in Sudan. This article reports the results of a clinical trial to test the effectiveness of injectable PM either alone (in a higher dose) or in combination with sodium stibogluconate (SSG) against the standard SSG monotherapy treatment in four East African countries—Sudan, Kenya, Ethiopia and Uganda. The study showed that the combination of SSG &PM was as efficacious and safe as the standard SSG treatment, with the advantages of being cheaper and requiring only 17 days rather than 30 days of treatment. In March 2010, a WHO Expert Committee recommended the use of the SSG & PM combination as a first line treatment for VL in East Africa

    The Antioxidant Activity of New Coumarin Derivatives

    Get PDF
    The antioxidant activity of two synthesized coumarins namely, N-(4,7-dioxo-2- phenyl-1,3-oxazepin-3(2H,4H,7H)-yl)-2-(2-oxo-2H-chromen-4-yloxy)acetamide 5 and N-(4-oxo-2-phenylthiazolidin-3-yl)-2-(2-oxo-2H-chromen-4-yloxy)acetamide 6 were studied with the DPPH, hydrogen peroxide and nitric oxide radical methods and compared with the known antioxidant ascorbic acid. Compounds 5 and 6 were synthesized in a good yield from the addition reaction of maleic anhydride or mercaptoacetic acid to compound 4, namely N′-benzylidene-2-(2-oxo-2H-chromen-4-yloxy)acetohydrazide. Compound 4 was synthesized by the condensation of compound 3, namely 2-(2-oxo-2H-chromen-4-yloxy) acetohydrazide, with benzaldehyde. Compound 3, however, was synthesized from the addition of hydrazine to compound 2, namely ethyl 2-(2-oxo-2H-chromen-4-yloxy)acetate, which was synthesized from the reaction of ethyl bromoacetate with 4-hydroxycoumarin 1. Structures for the synthesized coumarins 2–6 are proposed on the basis of spectroscopic evidence

    Efficacy and Safety of AmBisome in Combination with Sodium Stibogluconate or Miltefosine and Miltefosine Monotherapy for African Visceral Leishmaniasis: Phase II Randomized Trial.

    Get PDF
    BACKGROUND: SSG&PM over 17 days is recommended as first line treatment for visceral leishmaniasis in eastern Africa, but is painful and requires hospitalization. Combination regimens including AmBisome and miltefosine are safe and effective in India, but there are no published data from trials of combination therapies including these drugs from Africa. METHODS: A phase II open-label, non-comparative randomized trial was conducted in Sudan and Kenya to evaluate the efficacy and safety of three treatment regimens: 10 mg/kg single dose AmBisome plus 10 days of SSG (20 mg/kg/day), 10 mg/kg single dose AmBisome plus 10 days of miltefosine (2.5mg/kg/day) and miltefosine alone (2.5 mg/kg/day for 28 days). The primary endpoint was initial parasitological cure at Day 28, and secondary endpoints included definitive cure at Day 210, and pharmacokinetic (miltefosine) and pharmacodynamic assessments. RESULTS: In sequential analyses with 49-51 patients per arm, initial cure was 85% (95% CI: 73-92) in all arms. At D210, definitive cure was 87% (95% CI: 77-97) for AmBisome + SSG, 77% (95% CI 64-90) for AmBisome + miltefosine and 72% (95% CI 60-85) for miltefosine alone, with lower efficacy in younger patients, who weigh less. Miltefosine pharmacokinetic data indicated under-exposure in children compared to adults. CONCLUSION: No major safety concerns were identified, but point estimates of definitive cure were less than 90% for each regimen so none will be evaluated in Phase III trials in their current form. Allometric dosing of miltefosine in children needs to be evaluated. TRIAL REGISTRATION: The study was registered with ClinicalTrials.gov, number NCT01067443

    Geographical Variation in the Response of Visceral Leishmaniasis to Paromomycin in East Africa: A Multicentre, Open-Label, Randomized Trial

    Get PDF
    Visceral leishmaniasis (VL) is a fatal parasitic disease with 500,000 new cases each year according to WHO estimates. New and better treatment options are urgently needed in disease endemic areas due to the long courses, toxicity and development of resistance to current treatments. Recently, the antibiotic paromomycin was tested and registered in India to treat this disease. The current study describes a clinical trial to test the effectiveness of injectable paromomycin, either alone or in combination with the standard drug sodium stibogluconate in three East African countries—Sudan, Kenya and Ethiopia. The study showed that at the same paromomycin dose that was successfully used and registered in India, a far poorer outcome was obtained, particularly in Sudan, suggesting that there are either differences in the patients ability to respond to the drug or in the susceptibility of parasites in East Africa compared with those in India. However, no major safety concerns were noted with the treatment. Further research was initiated to see if a higher dose of paromomycin would perform better, especially in Sudan. The results of this and the performance of the combination arm will be reported later. Our study highlights the importance of considering geographical differences to treatment responses

    Multiplicity dependence of jet-like two-particle correlations in p-Pb collisions at sNN\sqrt{s_{NN}} = 5.02 TeV

    Full text link
    Two-particle angular correlations between unidentified charged trigger and associated particles are measured by the ALICE detector in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV. The transverse-momentum range 0.7 <pT,assoc<pT,trig< < p_{\rm{T}, assoc} < p_{\rm{T}, trig} < 5.0 GeV/cc is examined, to include correlations induced by jets originating from low momen\-tum-transfer scatterings (minijets). The correlations expressed as associated yield per trigger particle are obtained in the pseudorapidity range η<0.9|\eta|<0.9. The near-side long-range pseudorapidity correlations observed in high-multiplicity p-Pb collisions are subtracted from both near-side short-range and away-side correlations in order to remove the non-jet-like components. The yields in the jet-like peaks are found to be invariant with event multiplicity with the exception of events with low multiplicity. This invariance is consistent with the particles being produced via the incoherent fragmentation of multiple parton--parton scatterings, while the yield related to the previously observed ridge structures is not jet-related. The number of uncorrelated sources of particle production is found to increase linearly with multiplicity, suggesting no saturation of the number of multi-parton interactions even in the highest multiplicity p-Pb collisions. Further, the number scales in the intermediate multiplicity region with the number of binary nucleon-nucleon collisions estimated with a Glauber Monte-Carlo simulation.Comment: 23 pages, 6 captioned figures, 1 table, authors from page 17, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/161
    corecore