Adsorptive Removal of Chromium (VI) from Aqueous Solution Using Cow Hooves.

Aim: To investigate the use of Nigerian cow hooves for the removal of chromium VI from aqueous solution. Place and Duration: Chemistry Laboratory, Federal University of Technology, Akure and Chemistry Laboratory of Afe Babalola University, Ado-Ekiti, Nigeria, from September 2011 to June 2012. Methodology: The adsorption process, which was carried out through batch method, was investigated over a range of pH (2-7), agitation time (0-150 mins) and adsorbent mass (1.0-3.0 g per 50 mL of metal solution). The adsorption isotherms were obtained using initial metal concentrations ranging from15 to100 mgL-1. After agitation, the resultant solution was analyzed for Cr (VI) using Atomic Absorption Spectrophotometer. Results: The optimum operating parameters obtained for the adsorption process are pH 2 (89.5% removal) and time of 30 mins (34.4% removal) while the highest metal uptake (mgg-1) was recorded for 1g of the adsorbent per 50ml of solution. Langmuir, Freundlich and Dubinin-Raduskevich (D-R) isotherm models were applied to describe the experimental data. The Langmuir maximum adsorption capacities of the cow hoof for Cr (VI) at 298, 308 and 318 K were determined to be 3.57, 4.81 and 5.71 mgg-1 respectively. Freundlich isotherm model fitted the equilibrium data better than Langmuir and D-R models. The mean free energy (E) which was calculated from D-R model indicated that the sorption process was dominated by physisorption mechanism. The adsorption kinetics was found to follow the pseudo-second-order model. Conclusion: This study revealed that cow hoof powder can be used as a low cost adsorbent for the removal of Cr (VI) from wastewater under the optimum conditions of pH 2 and contact time of 30mins while the thermodynamic parameters- ΔG0, ΔH0 and ΔS0 indicated that the adsorption process was endothermic, feasible and spontaneous

Distribution of heavy metals in fish organs, associated water and sediment from Ero Dam, Ekiti State, Nigeria

An investigation into the distribution of lead, manganese, copper, zinc, mercury, iron, chromium and cadmium in the sediment, water and the organs of Oreochromisniloticus, Tilapia zillii, African catfish(Clarias gariepinus) and Citharinus citerus obtained from Ero Dam in Ikun-Ekiti, Ekiti State, Nigeria was undertaken. This was done to ascertain the presence of these metals in the three matrixes and to determine the bioaccumulation factors of these metals in the organs of these fishes. The three matrixes were differently digested and analysed for heavy metals using Atomic Absorption Spectrophotometer (Buck 200). Hg was determined via cold vapour generation. The levels of the metals in water were very much lower than their corresponding concentrations in the sediment. In the same vein, concentrations of the metals in the fish organs were higher than those recorded for the water except Cu and Mn that showed slight variations. The most concentrated metal in the organs of the four fish species was Zn which recorded concentrations (mg/kg) ranging from 7.36±0.03 in the head of Clarias gariepinus to 8.12±0.13 in that of Citharinus citerus. In Clarias gariepinus,Cr, Cd and Hg were only detected in its gills. On the contrary, all the metals were detected in the organs of Oreochromis niloticus and Tilapia zillii.Zn, Mn and Fe were the three most abundant metals in the organs of these fishes. The highly toxic metals (Pb, Cd and Hg) in this determination were either not detected or detected at low levels. It is obvious from this work that Zn was bioaccumulated most in the organs of each fish. It is certain that heavy metals are present in Ero dam but in low concentrations. This calls forconstant monitoring because as industries are established inEkiti State, Nigeria, the level of heavy metals inthis dam may increase

Prevalence and Prognostic Features of ECG Abnormalities in Acute Stroke: Findings From the SIREN Study Among Africans

Background Africa has a growing burden of stroke with associated high morbidity and a 3-year fatality rate of 84%. Cardiac disease contributes to stroke occurrence and outcomes, but the precise relationship of abnormalities as noted on a cheap and widely available test, the electrocardiogram (ECG), and acute stroke outcomes have not been previously characterized in Africans. Objectives The study assessed the prevalence and prognoses of various ECG abnormalities among African acute stroke patients encountered in a multisite, cross-national epidemiologic study. Methods We included 890 patients from Nigeria and Ghana with acute stroke who had 12-lead ECG recording within first 24 h of admission and stroke classified based on brain computed tomography scan or magnetic resonance imaging. Stroke severity at baseline was assessed using the Stroke Levity Scale (SLS), whereas 1-month outcome was assessed using the modified Rankin Scale (mRS). Results Patients\u27 mean age was 58.4 ± 13.4 years, 490 were men (55%) and 400 were women (45%), 65.5% had ischemic stroke, and 85.4% had at least 1 ECG abnormality. Women were significantly more likely to have atrial fibrillation, or left ventricular hypertrophy with or without strain pattern. Compared to ischemic stroke patients, hemorrhagic stroke patients were less likely to have atrial fibrillation (1.0% vs. 6.7%; p = 0.002), but more likely to have left ventricular hypertrophy (64.4% vs. 51.4%; p = 0.004). Odds of severe disability or death at 1 month were higher with severe stroke (AOR: 2.25; 95% confidence interval: 1.44 to 3.50), or atrial enlargement (AOR: 1.45; 95% confidence interval: 1.04 to 2.02). Conclusions About 4 in 5 acute stroke patients in this African cohort had evidence of a baseline ECG abnormality, but presence of any atrial enlargement was the only independent ECG predictor of death or disability

Exploring Overlaps Between the Genomic and Environmental Determinants of LVH and Stroke: A Multicenter Study in West Africa

Background Whether left ventricular hypertrophy (LVH) is determined by similar genomic and environmental risk factors with stroke, or is simply an intermediate stroke marker, is unknown. Objectives We present a research plan and preliminary findings to explore the overlap in the genomic and environmental determinants of LVH and stroke among Africans participating in the SIREN (Stroke Investigative Research and Education Network) study. Methods SIREN is a transnational, multicenter study involving acute stroke patients and age-, ethnicity-, and sex-matched control subjects recruited from 9 sites in Ghana and Nigeria. Genomic and environmental risk factors and other relevant phenotypes for stroke and LVH are being collected and compared using standard techniques. Results This preliminary analysis included only 725 stroke patients (mean age 59.1 ± 13.2 years; 54.3% male). Fifty-five percent of the stroke subjects had LVH with greater proportion among women (51.6% vs. 48.4%; p \u3c 0.001). Those with LVH were younger (57.9 ± 12.8 vs. 60.6 ± 13.4; p = 0.006) and had higher mean systolic and diastolic blood pressure (167.1/99.5 mm Hg vs 151.7/90.6 mm Hg; p \u3c 0.001). Uncontrolled blood pressure at presentation was prevalent in subjects with LVH (76.2% vs. 57.7%; p \u3c 0.001). Significant independent predictors of LVH were age \u3c45 years (adjusted odds ratio [AOR]: 1.91; 95% confidence interval [CI]: 1.14 to 3.19), female sex (AOR: 2.01; 95% CI: 1.44 to 2.81), and diastolic blood pressure \u3e 90 mm Hg (AOR: 2.10; 95% CI: 1.39 to 3.19; p \u3c 0.001). Conclusions The prevalence of LVH was high among stroke patients especially the younger ones, suggesting a genetic component to LVH. Hypertension was a major modifiable risk factor for stroke as well as LVH. It is envisaged that the SIREN project will elucidate polygenic overlap (if present) between LVH and stroke among Africans, thereby defining the role of LVH as a putative intermediate cardiovascular phenotype and therapeutic target to inform interventions to reduce stroke risk in populations of African ancestry

Dominant modifiable risk factors for stroke in Ghana and Nigeria (SIREN): a case-control study

Summary: Background: Sub-Saharan Africa has the highest incidence, prevalence, and fatality from stroke globally. Yet, only little information about context-specific risk factors for prioritising interventions to reduce the stroke burden in sub-Saharan Africa is available. We aimed to identify and characterise the effect of the top modifiable risk factors for stroke in sub-Saharan Africa. Methods: The Stroke Investigative Research and Educational Network (SIREN) study is a multicentre, case-control study done at 15 sites in Nigeria and Ghana. Cases were adults (aged ≥18 years) with stroke confirmed by CT or MRI. Controls were age-matched and gender-matched stroke-free adults (aged ≥18 years) recruited from the communities in catchment areas of cases. Comprehensive assessment for vascular, lifestyle, and psychosocial factors was done using standard instruments. We used conditional logistic regression to estimate odds ratios (ORs) and population-attributable risks (PARs) with 95% CIs. Findings: Between Aug 28, 2014, and June 15, 2017, we enrolled 2118 case-control pairs (1192 [56%] men) with mean ages of 59·0 years (SD 13·8) for cases and 57·8 years (13·7) for controls. 1430 (68%) had ischaemic stoke, 682 (32%) had haemorrhagic stroke, and six (<1%) had discrete ischaemic and haemorrhagic lesions. 98·2% (95% CI 97·2–99·0) of adjusted PAR of stroke was associated with 11 potentially modifiable risk factors with ORs and PARs in descending order of PAR of 19·36 (95% CI 12·11–30·93) and 90·8% (95% CI 87·9–93·7) for hypertension, 1·85 (1·44–2·38) and 35·8% (25·3–46·2) for dyslipidaemia, 1·59 (1·19–2·13) and 31·1% (13·3–48·9) for regular meat consumption, 1·48 (1·13–1·94) and 26·5% (12·9–40·2) for elevated waist-to-hip ratio, 2·58 (1·98–3·37) and 22·1% (17·8–26·4) for diabetes, 2·43 (1·81–3·26) and 18·2% (14·1–22·3) for low green leafy vegetable consumption, 1·89 (1·40–2·54) and 11·6% (6·6–16·7) for stress, 2·14 (1·34–3·43) and 5·3% (3·3–7·3) for added salt at the table, 1·65 (1·09–2·49) and 4·3% (0·6–7·9) for cardiac disease, 2·13 (1·12–4·05) and 2·4% (0·7–4·1) for physical inactivity, and 4·42 (1·75–11·16) and 2·3% (1·5–3·1) for current cigarette smoking. Ten of these factors were associated with ischaemic stroke and six with haemorrhagic stroke occurrence. Interpretation: Implementation of interventions targeting these leading risk factors at the population level should substantially curtail the burden of stroke among Africans. Funding: National Institutes of Health