Process Simulation and Optimization of Biodiesel Production from Algae Biomass

There is need to further examine optimization of biodiesel production from renewable sources. In this study, we report the optimization of biodiesel produced from microalgae biomass using the CHEMCAD process simulator. Results show that the overall molar flow and energy was calculated to be 7.010kmoles/h and -4936.5MJ/h respectively. And also the liquid viscosity of the microalgae oil is greater than that of the biodiesel produced

A pilot survey of impression materials and techniques used by dentists in the fabrication of fixed indirect restorations

Objective: To assess the choice of impression material and impression technique used by Nigerian dentists for the fabrication of cast restoration. Method: A self administered questionnaire was distributed to dentists present at two national dental meeting held at Abuja and Lagos in 2011. The questionnaire assessed their choice of impression materials and technique. Result: Fifty one out of 70 questionnaires were returned filled giving a response rate of 73%. There were 54.9% of the respondents who reported addition curing silicone impression as their first choice material for cast restorations, while 27.4% use alginate as first choice impression. The use of stock plastic trays by the respondents was significantly higher than metal and custom trays. Two-third of the respondents poured their impressions within one hour. All the respondents poured alginate impression after 15 minutes. A significantly high percentage (76%) of the respondents did not retract the free gingival before taking impression. Conclusion: The use of alginate impressions to produce cast restorations was common among the respondents. Since no previous study has documented the use of alginate to produce accurate fitting cast restorations, there is need to investigate the accuracy of alginate impressions in a clinical setting

Magnetic mineral exploration using ground magnetic survey data of Tajimi Area, Lokoja

Ground magnetic survey is an essential geophysical method employed in locating subsurface magnetic materials for possible exploration. In geophysics, the  anomalous magnetization might be associated with local mineralization that is potentially of commercial interest. Hence a ground magnetic survey was carried out at a site in Tajimi area of Lokoja, Kogi State, Nigeria. The study is aimed at locating the position of iron deposited minerals within the study area. The study area lies within Latitude 800292ˈN to 800625ˈN and Longitude 605833ˈE to 606167ˈE in the basement complex of Southern Nigeria. A total of fifteen magnetic transverse lines were established in an E-W direction in the study area covering 140m by 75m. Data were taken and recorded using Proton Precession magnetometer; the data were presented in magnetic profiles, 2D contour map and 3D surface map which aided the qualitatively interpretation. The study area was characterized by  completely varying magnetic anomaly amplitudes across the field. The field data were quantitatively interpreted and the results gave values for the total component  measurements of the ground magnetic anomaly that varied between a minimum  negative peak value of about -23428.7nT and a maximum positive peak value of  about 5840.9nT. The residual anomalies obtained were plotted against distance  using Microsoft Excel and Analytic signal method was used to estimates the depth to the magnetic source body. The estimated depths of the magnetic source  body/rocks from the Earth surface fall in the interval of 1.28m to 13.57m, which  indicates the magnetic source body suspected to be magnetic mineral, are near surface features. Hence a careful analysis of the magnetic anomaly maps can give vital information about the magnetic distribution and mineral potential of the studyarea at Tajimi

945-65 Effect of Left Anterior Hemiblock on the Sensitivity of Exercise Stress Tests

We had observed a relatively high frequency of false negative stress electrocardiograms compared with SPECT thallium scintigraphy in patients with LAHB.PurposeTo assess the effect of LAHB on the sensitivity of exercise induced ST depressions for ischemia compared with SPECT thallium scintigraphyMethodsA 5–year retrospective analysis of all treadmill thallium stress tests performed in our exercise laboratory was performed. Patients with LBBB, RBBB, IVCD, LVH or <85% of maximal HR were excluded.Study groupn=25 (16 M, 9 F, ages 35–87)Matched controlsn=18.Results(1) The sensitivity of ST depressions for ischemia in the study group was 30% compared with 71%in the control group, the specificities were 90% and 75% respectively.(2) There was no significant association between presence of ischemia on ECG and on SPECT thallium scans in the study group, while an association was found in the control group (p<0.01).ConclusionsThe sensitivity of exercise stress tests for ischemia is low in the presence left anterior hemiblock

Absolute quantitation of coronary steal induced by intravenous dipyridamole

AbstractOBJECTIVESThe study was done to determine whether coronary steal (defined as an absolute decrease in perfusion from resting blood flow) is induced by intravenous (IV) dipyridamole in patients with severe coronary artery disease (CAD).BACKGROUNDMyocardial ischemia during coronary vasodilation is usually attributed to coronary steal. However, there is limited data on the absolute magnitude of coronary steal in humans.METHODSEighteen patients with multivessel CAD underwent dynamic positron emission tomography (PET) imaging with 13NH3at rest and after infusion of IV dipyridamole. Eight myocardial sectors were analyzed per short axis slice and myocardial blood flow calculated with a two-compartment model in absolute terms.RESULTSCoronary steal occurred in 8 of the 18 patients. In the 8 patients with coronary steal, myocardial blood flow decreased from 90 ± 18 ml/100 g/min at rest to 68 ± 27 ml/100 g/min following dipyridamole in the segments with steal, and increased from 87 ± 19 to 138 ± 16 ml/100 g/min following dipyridamole in the segments without steal. Significant clinical correlates of coronary steal were either ST elevation or the combination of ST depression and angina.CONCLUSIONSCoronary vasodilation with IV dipyridamole is associated with significant reductions in blood flow to collateral-dependent myocardium consistent with coronary steal in about 45% of patients with severe CAD

Correlation of Prehypertension with Left Ventricular Mass Assessed by Cardiac Magnetic Resonance Imaging

Introduction. The purpose of this observational cross-sectional study was to assess left ventricular mass (LVM) in prehypertensive individuals in comparison to normotensives and to determine if central blood pressure (BP) correlates better with LVM index (LVMI) than brachial BP. Methods and Result. Brachial and central BP measurements were completed at first visit and at 4 weeks in 65 healthy volunteers who were at least 40 years old and not on medication. Subjects were divided into two groups of normotensives and prehypertensives based on JNC-7 criteria and LVM was obtained using cardiac magnetic resonance imaging. Prehypertensives had significantly higher LVMI compared to normotensives (P<0.01). Brachial and central BP also both positively correlate with LVMI (r=0.460, P<0.01; r=0.318, P=0.012, resp.) in both groups and neither method was superior to the other. After multivariate regression analysis and adjusting for cardiovascular risk factors, prehypertension remained an independent determinant of LVM. Conclusion. Prehypertension is associated with cardiovascular target organ damage, and central BP was not superior to brachial BP or vice versa for association with LVMI

Visually estimated ejection fraction by two dimensional and triplane echocardiography is closely correlated with quantitative ejection fraction by real-time three dimensional echocardiography

<p>Abstract</p> <p>Background</p> <p>Visual assessment of left ventricular ejection fraction (LVEF) is often used in clinical routine despite general recommendations to use quantitative biplane Simpsons (BPS) measurements. Even thou quantitative methods are well validated and from many reasons preferable, the feasibility of visual assessment (eyeballing) is superior. There is to date only sparse data comparing visual EF assessment in comparison to quantitative methods available. The aim of this study was to compare visual EF assessment by two-dimensional echocardiography (2DE) and triplane echocardiography (TPE) using quantitative real-time three-dimensional echocardiography (RT3DE) as the reference method.</p> <p>Methods</p> <p>Thirty patients were enrolled in the study. Eyeballing EF was assessed using apical 4-and 2 chamber views and TP mode by two experienced readers blinded to all clinical data. The measurements were compared to quantitative RT3DE.</p> <p>Results</p> <p>There were an excellent correlation between eyeballing EF by 2D and TP vs 3DE (r = 0.91 and 0.95 respectively) without any significant bias (-0.5 ± 3.7% and -0.2 ± 2.9% respectively). Intraobserver variability was 3.8% for eyeballing 2DE, 3.2% for eyeballing TP and 2.3% for quantitative 3D-EF. Interobserver variability was 7.5% for eyeballing 2D and 8.4% for eyeballing TP.</p> <p>Conclusion</p> <p>Visual estimation of LVEF both using 2D and TP by an experienced reader correlates well with quantitative EF determined by RT3DE. There is an apparent trend towards a smaller variability using TP in comparison to 2D, this was however not statistically significant.</p

Improved functionalization of oleic acid-coated iron oxide nanoparticles for biomedical applications

Superparamagnetic iron oxide nanoparticles can providemultiple benefits for biomedical applications in aqueous environments such asmagnetic separation or magnetic resonance imaging. To increase the colloidal stability and allow subsequent reactions, the introduction of hydrophilic functional groups onto the particles’ surface is essential. During this process, the original coating is exchanged by preferably covalently bonded ligands such as trialkoxysilanes. The duration of the silane exchange reaction, which commonly takes more than 24 h, is an important drawback for this approach. In this paper, we present a novel method, which introduces ultrasonication as an energy source to dramatically accelerate this process, resulting in high-quality waterdispersible nanoparticles around 10 nmin size. To prove the generic character, different functional groups were introduced on the surface including polyethylene glycol chains, carboxylic acid, amine, and thiol groups. Their colloidal stability in various aqueous buffer solutions as well as human plasma and serum was investigated to allow implementation in biomedical and sensing applications.status: publishe