Effect of zinc supplementation on serum mlondealdehyde and lipid profiles on beta thalassemia major patients

Objectives: Thalassemic patients are seriously at risk of serum dislipidemia, zinc deficiency and tissue damage due to oxidative stress induced by iron storage. In biologic systems, zinc may interact with iron and inhibit oxidative and reductive reactions resulted by iron and other chimiooxidative agents. The aim of this study was to evaluate the effect of zinc supplementation on serum Malondealdehyde (MDA) and lipid profiles in beta thalassemia major patients. Methods: In this clinical trial, 60 beta thalassemia major patients (male & female) older than 18 years old were assigned randomly in two groups as intervention and control groups(30 per group). The intervention group ingested zinc supplement as 220 mg zinc sulfate capsule contented 50 mg elemental zinc daily for 3 months. The control group did not receive any supplement in that time. Information about general characteristics, weight, height and dietary intake were gathered before and after the end of study. Blood samples were obtained from each subject prior and after the study and serum zinc, MDA, triglyceride, LDL-C and HDL-C levels were measured. Data analyzed with paired t-test, independent t-test and ANOVA. Results: Zinc supplementation caused significant increasing in daily caloric intake, body mass index, serum zinc and HDL-C levels and significant reduction in LDL-C levels in intervention group. No significant variations were observed for other variables in both of groups. Conclusion: Zinc supplementation had beneficial effects on serum lipid profiles in studied beta thalassemic patients and might have suitable role in delaying cardiovascular disease risks in these patients

Effects of vitamin e and zinc supplementation on antioxidants in beta thalassemia major patients

Objective: In beta thalassemic patients, tissue damage occurs due to oxidative stress and it happens because of the accumulation of iron in the body. This study was conducted to determine the effect of zinc and vitamin E supplementation on antioxidant status in beta-thalassemic major patients. Methods: This double blind randomized clinical trial was carried out on 120 beta thalassemic patients older than 18 years. Patients were randomly categorized in four groups. Zinc (50mg/day) and vitamin E (400mg/day) supplements were administered for former and latter group, respectively. In the third group both supplements were administered in similar doses. The fourth (control) group received no supplement. The effect of supplementations on serum zinc and vitamin E, superoxide dismutase (SOD), glutathione peroxidase (GPX), total antioxidant capacity (TAC) and body mass index (BMI) were measured at the beginning and the end of the study. Findings: Serum zinc levels in group 1 and 3 were significantly increased (P<0.007 and P<0.005, respectively). Serum vitamin E levels in group 2 and 3 were also increased significantly (P<0.001). Mean GPX activity in group1, 2 and 3 decreased significantly (P<0.015, P<0.032 and P<0.029, respectively). Mean SOD activity and TAC did not show significant change after supplementation. BMI had significant increase in all treated groups (P<0.001). Conclusion: Our results suggest that beta thalassemic patients have enhanced oxidative stress and administration of selective antioxidants may preclude oxidative damage. © 2011 by Pediatrics Center of Excellence, Children's Medical Center, Tehran University of Medical Sciences, All rights reserved

Split torque transmission load sharing

Split torque transmissions are attractive alternatives to conventional planetary designs for helicopter transmissions. The split torque designs can offer lighter weight and fewer parts but have not been used extensively for lack of experience, especially with obtaining proper load sharing. Two split torque designs that use different load sharing methods have been studied. Precise indexing and alignment of the geartrain to produce acceptable load sharing has been demonstrated. An elastomeric torque splitter that has large torsional compliance and damping produces even better load sharing while reducing dynamic transmission error and noise. However, the elastomeric torque splitter as now configured is not capable over the full range of operating conditions of a fielded system. A thrust balancing load sharing device was evaluated. Friction forces that oppose the motion of the balance mechanism are significant. A static analysis suggests increasing the helix angle of the input pinion of the thrust balancing design. Also, dynamic analysis of this design predicts good load sharing and significant torsional response to accumulative pitch errors of the gears

Thermodynamic analysis of turbulent combustion in a spark ignition engine. Experimental evidence

A method independent of physical modeling assumptions is presented to analyze high speed flame photography and cylinder pressure measurements from a transparent piston spark ignition research engine. The method involves defining characteristic quantities of the phenomena of flame propagation and combustion, and estimating their values from the experimental information. Using only the pressure information, the mass fraction curves are examined. An empirical burning law is presented which simulates such curves. Statistical data for the characteristics delay and burning angles which show that cycle to cycle fractional variations are of the same order of magnitude for both angles are discussed. The enflamed and burnt mass fractions are compared as are the rates of entrainment and burning

Initial Hypotheses for Modeling and Numerical Analysis of Rockfill and Earth Dams and Their Effects on the Results of the Analysis

© 2018 Mohammad Rashidi and Habib Rasouli. Since the behavior of earth dams is unreliable in different stages of construction, impounding, and exploitation, this matter is an unavoidable and essential issue with regard to the serious dangers caused by the failure of these important structures. It is crucial to evaluate the behavior of dams and examine the consistency between the carried out analyses and the behavioral parameters under different conditions in the lifespan of dams due to the uncertainty of the principles and hypotheses which have been adopted to analyze these structures. This objective will be accomplished through the help of correct numerical analyses. A series of hypotheses are adopted to simplify the parametric analyses before starting these analyses. The aim of this research is to develop and discuss these hypotheses. And so, the number of elements and their effects on the results of analyses were examined through the consolidation of unsaturated soil method, the compressible fluid method, correlated analysis, and uncorrelated analysis. It became clear after the numerical analyses that correlated analysis is a more precise method in comparison with the uncorrelated analysis method. However, this method is not economical when it comes to high dams and the replacement method is the uncorrelated analysis. Furthermore, the displacements are not that sensitive to the bulk modulus of water while the maximum settlement of the dam transfers from the middle of the dam's core to a location higher than that the core as the bulk modulus of water increases. However, pore water pressure is very sensitive to the bulk modulus of water

Finite Difference Schemes for Variable Order Time-Fractional First Initial Boundary Value Problems

The aim of the study is to obtain the numerical solution of first initial boundary value problem (IBVP) for semi-linear variable order fractional diffusion equation by using different finite difference schemes. We developed the three finite difference schemes namely explicit difference scheme, implicit difference scheme and Crank-Nicolson difference scheme, respectively for variable order type semi-linear diffusion equation. For this scheme the stability as well as convergence are studied via Fourier method. At the end, solution of some numerical examples are discussed and represented graphically using Matlab

Performance Management and Quality Assurance in Higher Education: A Conceptual Framework for a Blended Approach

This article proposes a framework to promote continuous quality improvement in higher education by bringing performance management and quality assurance together in a single approach. Blending the two systems eliminates the challenges of a two system approach. The study employed a quantitative methodology, with data collected by means of a closed-ended questionnaire administered to academic and administrative staff at four purposely selected public higher education institutions in Zimbabwe’s four major ethnic regions. The questionnaire drew insights from a framework developed by Silimperi et al. (2002) on essential elements for developing quality assurance systems. Fourteen elements were used to determine the possibility of blending the two systems. Of these, nine had a mean score of 4.0, three above 3.5 and two had a mean score of less than 3.5. These results indicate a high likelihood that the systems can be blended

Non-Fourier heat transport in metal-dielectric core-shell nanoparticles under ultrafast laser pulse excitation

Relaxation dynamics of embedded metal nanoparticles after ultrafast laser pulse excitation is driven by thermal phenomena of different origins the accurate description of which is crucial for interpreting experimental results: hot electron gas generation, electron-phonon coupling, heat transfer to the particle environment and heat propagation in the latter. Regardingthis last mechanism, it is well known that heat transport in nanoscale structures and/or at ultrashort timescales may deviate from the predictions of the Fourier law. In these cases heat transport may rather be described by the Boltzmann transport equation. We present a numerical model allowing us to determine the electron and lattice temperature dynamics in a spherical gold nanoparticle core under subpicosecond pulsed excitation, as well as that of the surrounding shell dielectric medium. For this, we have used the electron-phonon coupling equation in the particle with a source term linked with the laser pulse absorption, and the ballistic-diffusive equations for heat conduction in the host medium. Either thermalizing or adiabatic boundary conditions have been considered at the shell external surface. Our results show that the heat transfer rate from the particle to the matrix can be significantly smaller than the prediction of Fourier's law. Consequently, the particle temperature rise is larger and its cooling dynamics might be slower than that obtained by using Fourier's law. This difference is attributed to the nonlocal and nonequilibrium heat conduction in the vicinity of the core nanoparticle. These results are expected to be of great importance for analyzing pump-probe experiments performed on single nanoparticles or nanocomposite media

Analytic Approximate Solutions for MHD Boundary-Layer Viscoelastic Fluid Flow over Continuously Moving Stretching Surface by Homotopy Analysis Method with Two Auxiliary Parameters

In this study, a steady, incompressible, and laminar-free convective flow of a two-dimensional electrically conducting viscoelastic fluid over a moving stretching surface through a porous medium is considered. The boundary-layer equations are derived by considering Boussinesq and boundary-layer approximations. The nonlinear ordinary differential equations for the momentum and energy equations are obtained and solved analytically by using homotopy analysis method (HAM) with two auxiliary parameters for two classes of visco-elastic fluid (Walters’ liquid B and second-grade fluid). It is clear that by the use of second auxiliary parameter, the straight line region in ℏ-curve increases and the convergence accelerates. This research is performed by considering two different boundary conditions: (a) prescribed surface temperature (PST) and (b) prescribed heat flux (PHF). The effect of involved parameters on velocity and temperature is investigated

Analytic approximate solutions for unsteady boundary-layer flow and heat transfer due to a stretching sheet by homotopy analysis method

In this work, the homotopy analysis method is applied to study the unsteady&nbsp;boundary-layer flow and heat transfer due to a stretching sheet. The analytic solutions of&nbsp;the system of nonlinear ordinary differential equations are constructed in the series form.&nbsp;The convergence of the obtained series solutions is carefully analyzed. The velocity&nbsp;and temperature profiles are shown and the influence of non-dimensional parameter on&nbsp;the heat transfer is discussed in detail. The validity of our solutions is verified by the&nbsp;numerical results